Bernard Kirtman
YOU?
Author Swipe
View article: Perturbation Theory Treatment of Spin-Orbit Coupling. III: Coupled Perturbed Method for Solids
Perturbation Theory Treatment of Spin-Orbit Coupling. III: Coupled Perturbed Method for Solids Open
A previously proposed non-canonical coupled-perturbed Kohn-Sham density functional theory (KS-DFT)/Hartree-Fock (HF) treatment for spin-orbit coupling is here generalized to infinite periodic systems. The scalar-relativistic periodic KS-DF…
View article: First-Principles Calculation of the Optical Rotatory Power of Periodic Systems: Modern Theory with Modern Functionals
First-Principles Calculation of the Optical Rotatory Power of Periodic Systems: Modern Theory with Modern Functionals Open
An analysis of orbital magnetization in band insulators is provided. It is shown that a previously proposed electronic orbital angular-momentum operator generalizes the ``modern theory of orbital magnetization'' to include non-local Hamilt…
View article: CRYSTAL23: A Program for Computational Solid State Physics and Chemistry
CRYSTAL23: A Program for Computational Solid State Physics and Chemistry Open
The Crystal program for quantum-mechanical simulations of materials has been bridging the realm of molecular quantum chemistry to the realm of solid state physics for many years, since its first public version released back in 1988. This p…
View article: Perturbation Theory Treatment of Spin–Orbit Coupling, Part I: Double Perturbation Theory Based on a Single-Reference Initial Approximation
Perturbation Theory Treatment of Spin–Orbit Coupling, Part I: Double Perturbation Theory Based on a Single-Reference Initial Approximation Open
We develop a perturbation theory for solving the many-body Dirac equation within a given relativistic effective-core potential approximation. Starting from a scalar-relativistic unrestricted Hartree-Fock (SR UHF) solution, we carry out a d…
View article: Perturbation Theory Treatment of Spin–Orbit Coupling II: A Coupled Perturbed Kohn–Sham Method
Perturbation Theory Treatment of Spin–Orbit Coupling II: A Coupled Perturbed Kohn–Sham Method Open
A noncanonical coupled perturbed Kohn-Sham density functional theory (KS-DFT)/Hartree-Fock (HF) treatment of spin-orbit coupling (SOC) is provided. We take the scalar-relativistic KS-DFT/HF solution, obtained with a relativistic effective …
View article: The CRYSTAL code, 1976–2020 and beyond, a long story
The CRYSTAL code, 1976–2020 and beyond, a long story Open
CRYSTAL is a periodic ab initio code that uses a Gaussian-type basis set to express crystalline orbitals (i.e., Bloch functions). The use of atom-centered basis functions allows treating 3D (crystals), 2D (slabs), 1D (polymers), and 0D (mo…
View article: The VN2 negatively charged defect in diamond. A quantum mechanical investigation of the EPR response
The VN2 negatively charged defect in diamond. A quantum mechanical investigation of the EPR response Open
View article: Coupled Perturbation Theory Approach to Dual Basis Sets for Molecules and Solids. 1. General Theory and Application to Molecules
Coupled Perturbation Theory Approach to Dual Basis Sets for Molecules and Solids. 1. General Theory and Application to Molecules Open
We present a new coupled Hartree-Fock(HF)/Kohn-Sham DFT perturbation method that accounts for the effect of enlarging the basis set in electronic structure calculations. In contrast with previous approaches, our dual basis set treatment yi…
View article: Calculation of the Infrared Intensity of Crystalline Systems. A Comparison of Three Strategies Based on Berry Phase, Wannier Function, and Coupled-Perturbed Kohn–Sham Methods
Calculation of the Infrared Intensity of Crystalline Systems. A Comparison of Three Strategies Based on Berry Phase, Wannier Function, and Coupled-Perturbed Kohn–Sham Methods Open
International audience
View article: Quantum‐mechanical condensed matter simulations with CRYSTAL
Quantum‐mechanical condensed matter simulations with CRYSTAL Open
The latest release of the Crystal program for solid‐state quantum‐mechanical ab initio simulations is presented. The program adopts atom‐centered Gaussian‐type functions as a basis set, which makes it possible to perform all‐electron as we…
View article: Response Properties of Periodic Materials Subjected to External Electric and Magnetic Fields
Response Properties of Periodic Materials Subjected to External Electric and Magnetic Fields Open
View article: Frontiers of Quantum Chemistry
Frontiers of Quantum Chemistry Open
View article: Calculation of the dynamic first electronic hyperpolarizability <i>β</i>(−<i>ω</i> <i>σ</i>; <i>ω</i>1, <i>ω</i>2) of periodic systems. Theory, validation, and application to multi-layer MoS2
Calculation of the dynamic first electronic hyperpolarizability <i>β</i>(−<i>ω</i> <i>σ</i>; <i>ω</i>1, <i>ω</i>2) of periodic systems. Theory, validation, and application to multi-layer MoS2 Open
We describe our implementation of a fully analytical scheme, based on the 2n + 1 rule, for computing the coupled perturbed Hartree Fock and Kohn-Sham dynamic first hyperpolarizability tensor β(−ωσ; ω1, ω2) of periodic 1D (polymer), 2D (sla…
View article: Direct Piezoelectric Tensor of 3D Periodic Systems through a Coupled Perturbed Hartree–Fock/Kohn–Sham Method
Direct Piezoelectric Tensor of 3D Periodic Systems through a Coupled Perturbed Hartree–Fock/Kohn–Sham Method Open
A quasi-analytical theoretical method is devised, and implemented in the Crystal program, for calculation of the direct “proper” piezoelectric tensor of periodic systems including both the clamped-nuclei electronic and nuclear relaxation c…