Recent performance improvements to the DFT and TDDFT in GAMESS

Abstract

The general atomic and molecular electronic structure system (GAMESS) is a quantum chemistry package used in the first-principles modeling of complex molecular systems using density functional theory (DFT) as well as a number of other post-Hartree-Fock methods. Both DFT and time-dependent DFT (TDDFT) are of particular interest to the materials modeling community. Millions of CPU hours per year are expended by GAMESS calculations on high-performance computing systems; any substantial reduction in the time-to-solution for these calculations represents a significant saving in CPU hours. As part of this work, three areas for improvement were identified: (1) the exchange-correlation (XC) integration grid, (2) profiling and optimization of the DFT code, and (3) TDDFT parallelization. We summarize the work performed in these task areas and present the resulting performance improvement. These software enhancements are available in 12JAN2009R3 or later versions of GAMESS.

Theoretical and experimental study of solar cells based on nanostructured films of TiO2 sensitized with natural dyes extracted from Zea mays and Bixa orellana

“…The optimization of geometries of the ground state of the molecules was carried out employing density functional theory (DFT) calculations method with B3LYP functional and the basis set 6-31+G(d) using a code GAMESS. 12 The theoretical evaluation of the electron density in the HOMO and LUMO level of the dye molecules at the excited state were calculated using the time-dependent density functional theory (TDDFT) with B3LYP functional and the same basis set mentioned above. The TDDFT calculations consider the solvent effect on the dye structures by using the Polarizable Continuum Model (PCM) corresponding to water for C3G and acetonitrile for bixin.…”

Generalized Analytic Approach for Determination of Multidimensional Franck–Condon Factors: Simulated Photoelectron Spectra of Polynuclear Aromatic Hydrocarbons

“…In particular, the long-range corrected hybrid density functional, ωB97x-D, 37 was employed together with the Def2-TZVPPD basis set. 38 The army grade grid 39 was utilized for radial points in the Euler−MacLaurin quadrature and Lebedev grids (NRAD = 155 and NLEB = 1202, respectively). Full geometry optimizations were carried out and characterized through Hessian analysis to obtain minima stationary states (no imaginary frequency) and normal modes for FC calculations.…”

TDDFT versus GW/BSE Methods for Prediction of Light Absorption and Emission in a TADF Emitter

“…Calculations of ΔE are performed using the conductor-like polarizable continuum model (C-PCM) 44 in GAMESS. 58,59 II.D. Bethe−Salpeter Equation and TDDFT Methods.…”