Journal ArticleDOI
Force Constants and Dipole-Moment Derivatives of Molecules from Perturbed Hartree-Fock Calculations. I
J. Gerratt,Ian Mills +1 more
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TLDR
In this article, the Hartree-Fock wave function was used as an approximate wave function for the direct calculation of force constants and dipole-moment derivatives from SCF-MO wavefunctions.Abstract:
General expressions for the force constants and dipole‐moment derivatives of molecules are derived, and the problems arising in their practical application are reviewed. Great emphasis is placed on the use of the Hartree–Fock function as an approximate wavefunction, and a number of its properties are discussed and re‐emphasised. The main content of this paper is the development of a perturbed Hartree–Fock theory that makes possible the direct calculation of force constants and dipole‐moment derivatives from SCF–MO wavefunctions. Essentially the theory yields ∂φi / ∂RJα, the derivative of an MO with respect to a nuclear coordinate.read more
Citations
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Lattice dynamics calculations based on density-functional perturbation theory in real space
TL;DR: A real-space formalism for density-functional perturbation theory (DFPT) is derived and applied for the computation of harmonic vibrational properties in molecules and solids and the practical implementation using numeric atom-centered orbitals as basis functions is demonstrated.
Journal ArticleDOI
Analytic first derivatives of floating occupation molecular orbital-complete active space configuration interaction on graphical processing units
Edward G. Hohenstein,Marine E. F. Bouduban,Marine E. F. Bouduban,Marine E. F. Bouduban,Chenchen Song,Chenchen Song,Nathan Luehr,Nathan Luehr,Ivan S. Ufimtsev,Ivan S. Ufimtsev,Todd J. Martínez,Todd J. Martínez +11 more
TL;DR: It is demonstrated that FOMO-CASCI gradients are of similar computational expense to configuration interaction singles (CIS) or time-dependent density functional theory (TDDFT), and it is shown that FOSCI can describe multireference character of the electronic wavefunction.
Journal ArticleDOI
Ab initio theoretical optical rotations of small molecules
TL;DR: In this paper, the optical rotations of oxaziridines provided a nice correlation between the sign of optical rotation and absolute configuration, which is not obvious in the case of diaziridine and tetrahydrofurans.
Journal ArticleDOI
Embedded-cluster calculations in a numeric atomic orbital density-functional theory framework
Daniel Berger,Andrew J. Logsdail,Harald Oberhofer,Matthew R. Farrow,C. Richard A. Catlow,Paul Sherwood,Alexey A. Sokol,Volker Blum,Karsten Reuter +8 more
TL;DR: This work integrates the all-electron electronic structure code FHI-aims into the general ChemShell package for solid-state embedding quantum and molecular mechanical (QM/MM) calculations and implementation of pseudopotential functionality is implemented to describe cations at the QM/ MM boundary through effective core potentials to prevent spurious overpolarization of the electronic density.
Journal ArticleDOI
Analytical energy gradients for multiconfiguration self-consistent field wave functions with frozen core orbitals
TL;DR: In this paper, a method to calculate analytical energy gradients for multiconfiguration self-consistent field (MCSCF) wave functions with frozen core orbitals is presented.
References
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Book
Dynamical Theory of Crystal Lattices
Max Born,Kʿun Huang +1 more
TL;DR: Born and Huang's classic work on the dynamics of crystal lattices was published over thirty years ago, and it remains the definitive treatment of the subject as mentioned in this paper. But it is not the most complete work on crystal lattice dynamics.
Journal ArticleDOI
Forces in molecules
TL;DR: In this article, it was shown that the force on a nucleus in an atomic system is just the classical electrostatic force that would be exerted on this nucleus by other nuclei and by the electrons' charge distribution.