Performance of the Vienna ab initio simulation package (VASP) in chemical applications

Five different density functionals in combination with ultra-soft pseudopotentials and plane wave basis sets were used to optimize the geometries of common chemical systems using solid state program Vienna ab initio simulation package (VASP). These systems included diatomics, N-2, O-2, F-2 and CO, and carbon based organic systems, ethane, ethylene, acetylene, 1,3-butadiene, 1,3,5-hexatriene, benzene, biphenyl, naphtalene graphene, polyethylene and all-trans-polyacetylene. The four functionals based on the generalized gradient approximation gave very good agreement on bond lengths and angles as compared with each other with localized Gaussian basis set calculations and with experimental values. Reasonable results were also obtained for vibrational frequencies of selected normal modes of benzene and for torsional potentials of 1,3-butadiene and biphenyl. On the other hand, local density approximation tends to underestimate bond lengths. The performance of VASP for these properties is very similar to Gaussian type implementations of density functional theory explaining its successes in molecular, solid state, surface and polymer applications. (C) 2003 Elsevier Science B.V. All rights reserved.