This is a series of slides prepared by Heather Kulik (http://www.stanford.edu/~hkulik or email hkulik at stanford dot edu) for a talk given at the University of Pennsylvania in February 2012. It covers a basic introduction to DFT+U and related approaches for improving descriptions of transition metals and other systems with localized electrons.
Two efficient algorithms for drawing accurate and beautiful phonon dispersionTakeshi Nishimatsu
Purpose: easy drawing of accurate and beautiful phonon dispersion in first-principles calculations
See also: Draw phonon dispersion of Si with Quantum Espresso https://gist.github.com/t-nissie/32c10a148a7fc054b836
A basic tutorial on using Wannier90 with the VASP code. Includes a brief overview of Wannier functions, tips on how to build VASP with Wannier90 support, and how to use the VASP/Wannier90 interface to compute an HSE06 band structure and perform some other Wannier90 post processing.
Lecture: Interatomic Potentials Enabled by Machine LearningDanielSchwalbeKoda
Lecture for the 4th IKZ-FairMAT Winter School. Describes recent advances in neural network interatomic potentials, deep learning models accelerating quantum chemistry, and more.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
This is a series of slides prepared by Heather Kulik (http://www.stanford.edu/~hkulik or email hkulik at stanford dot edu) for a talk given at the University of Pennsylvania in February 2012. It covers a basic introduction to DFT+U and related approaches for improving descriptions of transition metals and other systems with localized electrons.
Two efficient algorithms for drawing accurate and beautiful phonon dispersionTakeshi Nishimatsu
Purpose: easy drawing of accurate and beautiful phonon dispersion in first-principles calculations
See also: Draw phonon dispersion of Si with Quantum Espresso https://gist.github.com/t-nissie/32c10a148a7fc054b836
A basic tutorial on using Wannier90 with the VASP code. Includes a brief overview of Wannier functions, tips on how to build VASP with Wannier90 support, and how to use the VASP/Wannier90 interface to compute an HSE06 band structure and perform some other Wannier90 post processing.
Lecture: Interatomic Potentials Enabled by Machine LearningDanielSchwalbeKoda
Lecture for the 4th IKZ-FairMAT Winter School. Describes recent advances in neural network interatomic potentials, deep learning models accelerating quantum chemistry, and more.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
II. Charge transport and nanoelectronics.
Quantum Hall Effect: 2D electron gas (2DEG) in magnetic field, Landau levels, de Haas-van Alphen and Shubnikov-de Haas Effects, integer and fractional quantum Hall effects, Spin Hall Effect.
Quantum transport: Transport regimes and mesoscopic quantum transport, Scattering theory of conductance and Landauer-Buttiker formalism, Quantum point contacts, Quantum electronics and selected examples of mesoscopic devices (quantum interference devices).
Tunneling: Scanning tunneling microscopy and spectroscopy (and wavefunction mapping in nanostructures and molecules), Nanoelectronic devices based on tunneling, Coulomb blockade, Single electron transistors, Kondo effect.
Molecular electronics: Donor-Acceptor systems, Nanoscale charge transfer, Electronic properties and transport in molecules and biomolecules; single molecule transistors.
Branislav K. Nikoli
ć
Department of Physics and Astronomy, University of Delaware, U.S.A.
PHYS 624: Introduction to Solid State Physics
http://www.physics.udel.edu/~bnikolic/teaching/phys624/phys624.html
This presentation is the introduction to Density Functional Theory, an essential computational approach used by Physicist and Quantum Chemist to study Solid State matter.
An updated tutorial on using Wannier90 with the VASP code for electronic-structure calculations. Includes tips on how to build VASP with Wannier90 support, how to use the VASP-to-Wannier90 interface, and a worked example of calculating the electronic band structure and density of states of SnS2 using the PBE and HSE06 functionals and the GW routines.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
II. Charge transport and nanoelectronics.
Quantum Hall Effect: 2D electron gas (2DEG) in magnetic field, Landau levels, de Haas-van Alphen and Shubnikov-de Haas Effects, integer and fractional quantum Hall effects, Spin Hall Effect.
Quantum transport: Transport regimes and mesoscopic quantum transport, Scattering theory of conductance and Landauer-Buttiker formalism, Quantum point contacts, Quantum electronics and selected examples of mesoscopic devices (quantum interference devices).
Tunneling: Scanning tunneling microscopy and spectroscopy (and wavefunction mapping in nanostructures and molecules), Nanoelectronic devices based on tunneling, Coulomb blockade, Single electron transistors, Kondo effect.
Molecular electronics: Donor-Acceptor systems, Nanoscale charge transfer, Electronic properties and transport in molecules and biomolecules; single molecule transistors.
Branislav K. Nikoli
ć
Department of Physics and Astronomy, University of Delaware, U.S.A.
PHYS 624: Introduction to Solid State Physics
http://www.physics.udel.edu/~bnikolic/teaching/phys624/phys624.html
This presentation is the introduction to Density Functional Theory, an essential computational approach used by Physicist and Quantum Chemist to study Solid State matter.
An updated tutorial on using Wannier90 with the VASP code for electronic-structure calculations. Includes tips on how to build VASP with Wannier90 support, how to use the VASP-to-Wannier90 interface, and a worked example of calculating the electronic band structure and density of states of SnS2 using the PBE and HSE06 functionals and the GW routines.
UCSD NANO 266 Quantum Mechanical Modelling of Materials and Nanostructures is a graduate class that provides students with a highly practical introduction to the application of first principles quantum mechanical simulations to model, understand and predict the properties of materials and nano-structures. The syllabus includes: a brief introduction to quantum mechanics and the Hartree-Fock and density functional theory (DFT) formulations; practical simulation considerations such as convergence, selection of the appropriate functional and parameters; interpretation of the results from simulations, including the limits of accuracy of each method. Several lab sessions provide students with hands-on experience in the conduct of simulations. A key aspect of the course is in the use of programming to facilitate calculations and analysis.
A Rapid and Innovative Method for Prediction of Spin Multiplicity and Spin St...iosrjce
Determination of spin multiplicity is very important for identification of spin state of different
molecules or ions. But, the conventional method of prediction of spin multiplicity by using formula (2S+1) is
time consuming. So, in this manuscript, I tried to show a rapid and simple method for prediction of spin
multiplicity value without calculating the total spin quantum number(S=∑s). This method is only applicable for
homo and hetero nuclear diatomic molecules and ions having total electron (01-20).
This is my published paper in IOSR JAC novemboe 2015 edition in the field of inorganic chemictry.By this method we can easily find the spin multiplicity value of any diatomic molecules having total electron no 1-20 ,without calculation total spin quantum no.This is most easy way to calculate spin multiplicity value and also time saving method with simple concept.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
DERIVATION OF MODIFIED BERNOULLI EQUATION WITH VISCOUS EFFECTS AND TERMINAL V...Wasswaderrick3
In this book, we use conservation of energy techniques on a fluid element to derive the Modified Bernoulli equation of flow with viscous or friction effects. We derive the general equation of flow/ velocity and then from this we derive the Pouiselle flow equation, the transition flow equation and the turbulent flow equation. In the situations where there are no viscous effects , the equation reduces to the Bernoulli equation. From experimental results, we are able to include other terms in the Bernoulli equation. We also look at cases where pressure gradients exist. We use the Modified Bernoulli equation to derive equations of flow rate for pipes of different cross sectional areas connected together. We also extend our techniques of energy conservation to a sphere falling in a viscous medium under the effect of gravity. We demonstrate Stokes equation of terminal velocity and turbulent flow equation. We look at a way of calculating the time taken for a body to fall in a viscous medium. We also look at the general equation of terminal velocity.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
6. FeO-GGA density of states
Density of states:
● Majority spin states are almost full, they are below EF
● Minority spin states are partially occupied at EF
metallic behavior→
7. FeO-GGA+U
Hubbard_U(1)=1.d-10,
Hubbard_U(2)=4.3,
Hubbard_U(3)=4.3
Hubbard U correction of Fe d-states:
Total occupations:
atom 1 Tr[ns(na)] (up, down, total) = 2.80479 2.80492 5.60971
atom 3 Tr[ns(na)] (up, down, total) = 4.99045 1.73174 6.72219
atom 4 Tr[ns(na)] (up, down, total) = 1.73173 4.99046 6.72219
Check minority spin occupations of either Fe atom:
atom 4 spin 1
eigenvalues:
0.095 0.216 0.216 0.603 0.603
eigenvectors:
0.000 0.848 0.030 0.085 0.037
0.333 0.034 0.047 0.002 0.584
0.333 0.009 0.072 0.467 0.119
0.000 0.030 0.848 0.037 0.085
0.333 0.078 0.003 0.410 0.176
0.095
0.216
0.603
Still partial occupations!
METALLIC
8. FeO-GGA+U density of states
Density of states:
We found a local minimum of DFT+U energy
functional, which is metallic !
9. FeO-GGA+U
Let us try to suggest a different possible electronic configuration to the system:
Check minority spin occupations of either Fe atom after the 1st iteration:
atom 4 spin 1
eigenvalues:
0.164 0.164 0.202 0.252 0.252
eigenvectors:
0.043 0.940 0.000 0.013 0.004
0.006 0.005 0.333 0.000 0.655
0.011 0.001 0.333 0.492 0.163
0.940 0.043 0.000 0.004 0.013
0.001 0.011 0.333 0.491 0.164
We want to drive the system to a configuration where the A1g state is fully occupied:
●
This state is singlet filling it→ completely will lead to an insulator
●
Physically, it points along the [111] direction, perpendicular to (111) AFM planes
10. FeO-GGA+U2
starting_ns_eigenvalue(3,2,2)=1.d0,
starting_ns_eigenvalue(3,1,3)=1.d0
Override the 3rd eigenvalue of the spin 2 of atom 2 and spin 1 of atom 3 with 1.d0:
eigenvalue
index
spin
index
atom type
index
Check the resulting minority spin occupations of either Fe atom:
atom 4 spin 1
eigenvalues:
0.091 0.091 0.240 0.240 0.996
eigenvectors:
0.009 0.002 0.617 0.372 0.000
0.010 0.650 0.000 0.007 0.333
0.419 0.241 0.006 0.001 0.333
0.002 0.009 0.372 0.617 0.000
0.561 0.099 0.004 0.003 0.333
●
A1g state is fully occupied
●
Other are almost empty.
11. FeO-GGA+U2 density of states
Density of states:
The insulating state is found !
Which of these local minima has lower energy?
total energy = -175.07464368 Ry
total energy = -175.16678519 Ry
DFT+U metallic
DFT+U insulating
●
A1g is completely full.
●
No partial occupations.
12. FeO-GGA+U2
What about other local energy minima?
●
There are others with lower energy!
●
How to find them? Physical intuition!→
Cococcioni et.al. PRB 71, 035105 (2005)
13. Calculation of U-NiO
If we use the unit cell, perturbing an atom
will perturb all the atoms of the same type
in the crystal.
We need a super cell to compute U
●
Perturbations can not be isolated
●
Interactions between periodic images
●
will interfere with each other.
Calculated value of U will converge with
increasing super cell size.
15. Calculation of U-NiO
Steps:
1.Perform the unperturbed scf run → nio_1.scf.out
2.Save the wavefunctions and potential in temp1
3.Reading the initial conditions from temp1, perturb the Ni-d orbitals by
Hubbard_alpha → ni.-0.15.out, ni.0.0.out, ni.0.15.out
This step concludes the perturbation of Ni-d states. Now we perturb O-p states
To do so, first shift the coordinates such that one O atom is at the origin
1.Perform the unperturbed scf run → nio_2.scf.out
2.Save the wavefunctions and potential in temp1
3.Reading the initial conditions from temp1, perturb the Ni-d orbitals by
Hubbard_alpha o→ .-0.15.out, o.0.0.out, o.0.15.out
This step concludes the perturbation of O-p states.
Now we can construct response matrices
16. Calculation of U-NiO
Response matrices by numerical derivative:
This step is performed for all the atoms by the program resp_mat.f90 in the folder Ucalc.
● Entries for the response matrices are generated by grepnalfa_nio_r16
For example:
grep 'Tr' ni.$con.out |tail -16|head -$at|tail -1|awk '{print $10}'
extracts the response of the atom ``$at'' to the perturbation of Ni d-states by ``$con''
which is used for constructing
likewise;
grep 'Tr' ni.$con.out |head -32|tail -16|head -$at|tail -1
| awk '{print $10}'
extracts the response of the atom ``$at'' to the perturbation of Ni d-states by ``$con''
which is used for constructing , since it reads the occupations after the first
iteration (head -32)
17. Calculation of U-NiO
Important checks:
●
The response matrices must be linear.
●
Screened (scf converged) and Kohn-Sham (with fixed Hubbard potential) responses
must coincide at zero perturbation.
e.g.
18. Calculation of U-NiO
Description of the input format for resp_mat.f90
&input_mat
ntyp = 2 # Number of types of atoms
na(1) = 8 # Number of atoms of type 1
na(2) = 8 # Number of atoms of type 2
nalfa = 3 # Number of perturbations
magn = .true. # .true. for magnetic systems,.false. otherwise.
filepos = 'pos_nio_r16' # file containing atomic positions
back = 'no' # to add neutralizing background, see PRB-71 35105 (05)
filednda = 'file.nio.r16' # file containing the names of dn*dat
n1 = 5
n2 = 5 # number of unit cells used for extrapolating
n3 = 5 # response matrices to larger supercells.
&end
This input is automatically generated and the executed by the script ucalc_nio_r16.j
19. Calculation of U-NiO
●
As we discussed earlier, calculated values of U converge with increasing super cell size.
●
However, super cell calculations are very expensive.
●
Instead, once can extrapolate to larger super cells; schematically:
We compute explicitly: extrapolate
●
Same U between nearest-neighbors
of the same kinds of pairs.
●
Further pairs, response is equated to 0
This step is also performed by resp_mat.f90
20. Calculation of U-NiO
16 4.07869507114729 18.2067600029958
128 4.77585513557480 18.9533524768798
432 4.80515746873350 19.0032555863967
1024 4.80681945930046 19.0062407730070
2000 4.80692778243639 19.0064368341791
Check Ur16.out:
Number of atoms
In the super cell
Calculated U
on Ni-d
Calculated U
on O-p
21. Exercise Cu2
O
● Cu2
O is a well-studied simple
semiconductor.
●
It is a parent structure for many
transparent conductive oxides.
●
Non-magnetic
● Eg
~ 2.2 eV
ATOMIC_POSITIONS {crystal}
Cu 0.25 0.25 0.25
Cu 0.75 0.25 0.75
Cu 0.75 0.75 0.25
Cu 0.25 0.75 0.75
O 0.00 0.00 0.00
O 0.50 0.50 0.50
ibrav=1, celldm(1)=8.21
nspin = 1
22. Exercise Cu2
O
●
Perform the GGA calculation and plot the DOS.
●
What is the band gap?
●
Compute U on Cu-d states using the linear response approach.
●
Is there a smaller super-cell than the 2x2x2 one (which has 48 atoms)?
●
Using the computed value of U, perform the GGA+U calculation.
●
Investigate the changes in the DOS.
●
How does projections on the atomic orbitals re-organize in the DOS?
●
How does the occupation matrices change? Which states get more filled?