01575nas a2200169   4500008004100000022001400041245015600055210006900211260007100280300001600351490000800367520084100375100001801216700002301234700001601257856013201273       2008                        eng d  a1089-563900aNoniterative density functional response approach: application to nonlinear optical properties of p-nitroaniline and its methyl-substituted derivatives0 aNoniterative density functional response approach application to  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a11266-112720 v1123 a<p>We report the effect of substitution, position of the substituent, and the symmetry on the nonlinear optical properties of p-nitroanline (PNA) and its derivatives using our implementation of the noniterative approximation of couple-perturbed Kohn-Sham (CPKS) equation in the deMon2k. Dipole moment, static polarizability, and first hyperpolarizability of these pi-conjugated donor-acceptor organic derivatives of PNA and its methyl-substituted analogs are calculated using our method at different exchange correlation functionals, namely, BP86, BPW91, and BLYP, using 6-31++G** basis set. A comparison of results obtained by our method with those obtained by MP2 (finite-field perturbation) method is presented in this paper. The effect of optical gap on charge transfer and subsequently on polarizabilities has been illustrated.</p>1 aSophy, K., B.1 aShedge, Sapana, V.1 aPal, Sourav  uhttps://library.ncl.res.in/content/noniterative-density-functional-response-approach-application-nonlinear-optical-properties-002125nas a2200181   4500008004100000022001400041245020900055210006900264260007100333300001400404490000800418520129500426100002301721700003001744700001601774700002401790856012901814       2010                        eng d  a1089-563900aComparison of the auxiliary density perturbation theory and the noniterative approximation to the coupled perturbed kohn-sham method: case study of the polarizabilities of disubstituted azoarene molecules0 aComparison of the auxiliary density perturbation theory and the   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a2357-23640 v1143 a<p>We present a theoretical study of the polarizabilities of free and disubstituted azoarenes employing auxiliary density perturbation theory (ADPT) and the noniterative approximation to the coupled perturbed Kohn-Sham (NIA-CPKS) method. Both methods are noniterative but use different approaches to obtain the perturbed density matrix. NIA-CPKS is different froth the conventional CPKS approach in that the perturbed Kohn-Sham matrix is obtained numerically, thereby yielding a single-step solution to CPKS. ADPT is an alternative approach to the analytical CPKS method in the framework of the auxiliary density functional theory. It is shown that the polarizabilities obtained using these two methods are in good agreement with each other. Comparisons are made for disubstituted azoarenes, which give support to the push-pull mechanism. Both methods reproduce the same trend for polarizabilities because of the substitution pattern of the azoarene moiety. Our results are consistent with the standard organic chemistry ``activating/deactivating'' sequence. We present the polarizabilities of the above molecules calculated with three different exchange-correlation functionals and two different auxiliary function sets. The computational advantages of both methods are also discussed.</p>1 aShedge, Sapana, V.1 aCarmona-Espindola, Javier1 aPal, Sourav1 aKoster, Andreas, M.  uhttps://library.ncl.res.in/content/comparison-auxiliary-density-perturbation-theory-and-noniterative-approximation-coupled-001566nas a2200169   4500008004100000022001400041245019600055210006900251260007300320300001200393490000800405520079500413100002301208700001601231700002501247856012401272       2011                        eng d  a0009-261400aValidation and application of auxiliary density perturbation theory and non-iterative approximation to coupled-perturbed Kohn-Sham approach for calculation of dipole-quadrupole polarizability0 aValidation and application of auxiliary density perturbation the  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a185-1900 v5103 a<p>Recently, two non-iterative approaches have been proposed to calculate response properties within density functional theory (DFT). These approaches are auxiliary density perturbation theory (ADPT) and the non-iterative approach to the coupled-perturbed Kohn-Sham (NIA-CPKS) method. Though both methods are non-iterative, they use different techniques to obtain the perturbed Kohn-Sham matrix. In this Letter, for the first time, both of these two independent methods have been used for the calculation of dipole-quadrupole polarizabilities. To validate these methods, three tetrahedral molecules viz., P-4; CH4 and adamantane (C10H16) have been used as examples. The comparison with MP2 and CCSD proves the reliability of the methodology. (C) 2011 Elsevier B. V. All rights reserved.</p>1 aShedge, Sapana, V.1 aPal, Sourav1 aKoester, Andreas, M.  uhttps://library.ncl.res.in/content/validation-and-application-auxiliary-density-perturbation-theory-and-non-iterative-002149nas a2200229   4500008004100000022001400041245011300055210006900168260005700237300000900294490000800303520130600311653000801617653003301625653003701658653002301695653001301718100002301731700002201754700001601776856012701792       2012                        eng d  a1432-881X00aBehaviour of density functional theory for electric response properties at distorted geometries of molecules0 aBehaviour of density functional theory for electric response pro  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcFEB  a10940 v1313 a<p>The role of exchange-correlation is well known for accurate calculations of electric response properties. The exchange-correlation functional in density functional theory (DFT) has been well studied for ground state equilibrium geometry. However, the behaviour of these functional in stretched geometries, where static correlation play an important role, has not been studied systematically, particularly for response electric properties. Thus, we present here the rigorous calculation of electric response properties at distorted geometries of the molecules. We have considered dipole polarizability and dipole-quadrupole polarizability for description of role of static and dynamic correlation for electric response properties. The calculations are performed with our new approach, noniterative approximation to coupled-perturbed Kohn-Sham method. These DFT results are compared with higher level ab initio such as coupled perturbed singles and doubles and fully correlated full CI. We have studied single, double and triple-bonded systems at different inter-nuclear separation. We report here the dipole polarizability and dipole-quadrupole polarizability of HF, BH, H2CO, CO and NO+. We also present the effect of basis and functional on polarizability and dipole-quadrupole polarizability.</p>10aDFT10aDipole-dipole polarizability10aDipole-quadrupole polarizability10aDistorted geometry10aNIA-CPKS1 aShedge, Sapana, V.1 aJoshi, Sayali, P.1 aPal, Sourav  uhttps://library.ncl.res.in/content/behaviour-density-functional-theory-electric-response-properties-distorted-geometries-001578nas a2200169   4500008004100000022001400041245012000055210006900175260007300244300001200317490000800329520087600337100002301213700001601236700002501252856013101277       2012                        eng d  a0009-261400aTheoretical study of frequency and temperature dependence of dipole-quadrupole polarizability of P-4 and adamantane0 aTheoretical study of frequency and temperature dependence of dip  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a146-1500 v5523 a<p>The frequency and temperature dependence of dipole-quadrupole polarizability of tetrahedral P-4 and adamantane molecules have been studied using first-principle all-electron density functional theory calculation. The recently developed time-dependent auxiliary density functional theory is extended for the calculation of dynamic dipole-quadrupole polarizabilities. Temperature effects are incorporated by Born-Oppenheimer molecular dynamics (BOMD) simulations recorded up to 100 ps. The dynamic dipole-quadrupole polarizabilities are calculated along these trajectories. The frequency and temperature effects can be significant for the accurate calculation of dipole-quadrupole polarizability. We have also identified the main reason for the observed discrepancy between experiment and theory in the case of adamantane. (c) 2012 Elsevier B.V. All rights reserved.</p>1 aShedge, Sapana, V.1 aPal, Sourav1 aKoester, Andreas, M.  uhttps://library.ncl.res.in/content/theoretical-study-frequency-and-temperature-dependence-dipole-quadrupole-polarizability-p-0