Joseph N. Kushick

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMethod for estimating the configurational entropy of macromoleculesMartin Karplus and Joseph N. KushickCite this: Macromolecules 1981, 14, 2, 325–332Publication Date (Print):March 1, 1981Publication History Published online1 May 2002Published inissue 1 March 1981https://doi.org/10.1021/ma50003a019RIGHTS & PERMISSIONSArticle Views4232Altmetric-Citations716LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEvaluation of the configurational entropy for proteins: application to molecular dynamics simulations of an α-helixRonald M. Levy, Martin Karplus, Joseph Kushick, and David PerahiaCite this: Macromolecules 1984, 17, 7, 1370–1374Publication Date (Print):July 1, 1984Publication History Published online1 May 2002Published inissue 1 July 1984https://pubs.acs.org/doi/10.1021/ma00137a013https://doi.org/10.1021/ma00137a013research-articleACS PublicationsRequest reuse permissionsArticle Views1291Altmetric-Citations229LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

The Lennard-Jones potential is separated into a purely repulsive and a purely attractive part, VR and VA, respectively. The velocity correlation function (vcf) is computed by molecular dynamics separately for (VR + VA) and for VR in both isotropic and nematic liquids for several thermodynamic states. It is found that in dense fluids, the results for these two different potentials are in qualitative agreement. The role of the attractive force is discussed. This work is motivated by the recent success of perturbation theories in connection with the equilibrium properties of fluids.

We have extended the molecular dynamics method to permit the simulation of systems containing cylindrically symmetric molecules with arbitrary eccentricity. This extension is accomplished by means of a potential energy function which models the primary interaction effects of molecular anisotropy, and which is mathematically convenient for computer use. The method is then applied to two problems, one involving the stability of the nematic liquid crystal phase, and the other illustrating the effect of cooperative reorientation on spectral line shapes.

It is shown that the angular velocity autocorrelation function for symmetric top molecules can in principle be determined from infrared and Raman band shapes, and from thermal neutron scattering when the molecular tumbling rate is slow compared with the relaxation of angular momentum. The theory is compared with molecular dynamics studies on a liquid crystal and an isotropic liquid.