The MovingGrid Effect in the Harmonic Vibrational Frequency Calculations with Numeric AtomCentered Orbitals
Abstract
When using atomcentered integration grids, the portion of the grid that belongs to a certain atom also moves when this atom is displaced. In the paper, we investigate the movinggrid effect in the calculation of the harmonic vibrational frequencies when using allelectron fullpotential numeric atomiccentered orbitals as the basis set. We find that, unlike the first order derivative (i.e., forces), the movinggrid effect plays an essential role for the second order derivatives (i.e., vibrational frequencies). Further analysis reveals that predominantly diagonal force constant terms are affected, which can be bypassed efficiently by invoking translational symmetry. Our approaches have been demonstrated in both finite (molecules) and extended (periodic) systems.
 Publication:

arXiv eprints
 Pub Date:
 December 2017
 DOI:
 10.48550/arXiv.1801.00166
 arXiv:
 arXiv:1801.00166
 Bibcode:
 2018arXiv180100166S
 Keywords:

 Physics  Computational Physics
 EPrint:
 J. Phys. Chem. A, 2020