ISSN:
1600-5724
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Representations of high-quality molecular electron densities are studied. An evaluation of restricted radial functions is made using a least-squares figure of merit, the molecular dipole and quadrupole moments, the electric fields at the nuclei, the electric-field gradients at the nuclei, an approximate energy and difference-density maps. For the heavy atom, a satisfactory representation has a fixed core function with a variable population and requires optimized dipolar core polarization functions, and an additional monopole term. The heavy-atom valence regions, and the H require expansions to at least the quadrupole level, with one Slater-type radial function per multipole and all exponents optimized. Additional valence radial functions and higher multipoles are required to give completely satisfactory difference-density maps but do not consistently improve the physical properties.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0567739482000515
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