The remarkable enneahydridorhenate dianion: ReH2-9

Abstract

All-electron, non-relativistic ab initio self-consistent field (SCF) quantum mechanical methods were applied to the unique enneahydridorhenate dianion (ReH2- 9, D 3h ). Three basis sets were constructed and used for rhenium: the (20s14p11d7f/17s11p8d2f) basis is loosely designated DZ; the (23s17p14d9f/18s14p10d3f) is similarly designated TZ; and TZ plus polarization plus diffuse is designated TZP +. The largest basis set, TZP +, has 24s20p15d10f primitive Gaussian functions contracted to 19s17p11d4f. Four basis sets were used for H: the (5s/3s) is designated TZ; (5s2p/3s2p) is designated TZ2P; (6s2p/4s2p) is designated QZ2P; and QZ2P plus one diffuse s function is designated QZ2P +. The well-known experimental D 3h structure was investigated, with the three independent internal coordinates optimized using analytic gradient techniques. The larger basis sets were handled using the direct SCF approach. The largest basis set for which the geometry was optimized was TZP + for Re and QZ2P + for H (with 252 basi...