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Biomedical subjects

J C Grossman

Publications and source records attributed to J C Grossman.

11 recordsLinked to original sources
PubMed2001

Linear-scaling quantum Monte Carlo calculations.

A method is presented for using truncated, maximally localized Wannier functions to introduce sparsity into the Slater determinant part of the trial wave function in quantum Monte Carlo calculations. When combined with an efficient numerical evaluation of these localized orbitals, the dominant cost in the calculation, namely, the evaluation of the Slater determinant, scales linearly with system size. This technique is applied to accurate total energy calculation of hydrogenated silicon clusters and carbon fullerenes containing 20-1000 valence electrons.

Journal Article↗
PubMed2001

High accuracy many-body calculational approaches for excitations in molecules.

Two state-of-the-art computational approaches: quantum Monte Carlo and GW with exciton effects [GW-BSE (Bethe-Salpeter equation)] are employed to calculate ionization potentials, electron affinities, and first excited singlet and triplet energies for the silane and methane molecules. Results are in excellent agreement between these dramatically different approaches and with available experiment. The optically forbidden triplet excitation in silane is predicted to lie roughly 1 eV higher than previously reported. In the GW-BSE method, we demonstrate that inclusion of off-diagonal matrix elements in the self-energy operator is crucial for an accurate picture.

Journal Article↗
PubMed1980

Undergraduate marijuana use as related to internal sensation novelty seeking and openness to experience.

Used 148 male and 130 female college students as Ss and replicated and expanded upon previous findings in marijuana personality research. It was found that the greater the self-reported frequency of marijuana use across Ss, the higher the cores on creativity and adventuresomeness tests tended to be and the lower the scores on authoritarianism tended to be. Males were more frequent users than females; Jews more frequent users than Protestants or Catholics. A new variable, internal sensation novelty seeking, was found to be correlated with self-reported frequency of marijuana use. Self-reported length of marijuana use was not related to any of the major variables, with the singular exception that after 2 years of use, expressed boredom with the environment decreased significantly.

Adult↗
PubMed1969

Some effects of punishment on pain-elicited aggression.

Painful mechanical tail-pinch elicited aggressive responses in paired rats; response-contingent electric shock to either forepaws or hindpaws suppressed fighting and stereotyped aggressive postures, including those in which dominance was expressed. There was no evidence that aggression was facilitated by shock that was contingent on pain-elicited aggressive responses. Aggressive responding recovered when shock was discontinued.

Aggression↗