$TDHF group (relevant for SCFTYP=RHF if RUNTYP=TDHF) This group permits the analytic calculation of various static and/or frequency dependent polarizabilities, with an emphasis on important NLO properties such as second and third harmonic generation. The method is programmed only for closed shell wavefunctions, at the semi-empirical or ab initio level. Ab initio calculations may be direct SCF, or parallel, if desired, except INIG=2. For a more general numerical approach to the static properties, see $FFCALC. For additional closed shell dynamic polarizabilities and spectra, see $TDHFX. To compute the hyperpolarizability for closed shell DFT, or to use fully general frequency combinations, see TDDFT=HPOL. There is a summary of all possible different types of polarizability computations in the 4th manual chapter. NFREQ = Number of frequencies to be used. (default=1) FREQ = An array of energy values in atomic units. For example: if NFREQ=3 then FREQ(1)=0.0,0.1,0.25. By default, only the static polarizabilities are computed. (default is freq(1)=0.0) The conversion factor from wavenumbers to Hartree is to divide by 219,474.6. To convert a wavelength to Hartree, compute FREQ=45.56/lamda, lambda in nm. MAXITA = Maximum number of iterations for an alpha computation. (default=100) MAXITU = Maximum number of iterations in the second order correction calculation. This applies to iterative beta values and all gammas. (default=100) DIIS = use the DIIS extrapolation using residual induced Fock matrix (default=.TRUE.). MAXDII = the maximum number of Fock matrices to be used in DIIS extrapolation (default=50). ATOL = Tolerance for convergence of first-order results. (default=1.0d-05) BTOL = Tolerance for convergence of second-order results. (default=1.0d-05) RETDHF = a flag to choose starting points for iterative calculations from best previous results. (default=.true.) * * * the following NLO properties are available * * * Note: alpha polarizabilities are always calculated. INIB = 0 turns off all beta computation (default) = 1 calculates only noniterative beta = 2 calculate iterative and noniterative beta The next flags allow further BETA tuning BSHG = Calculate beta for second harmonic generation. BEOPE = Calculate beta for electrooptic Pockels effect. BOR = Calculate beta for optical rectification. INIG = 0 turns off all gamma computation (default) = 1 calculates only noniterative gamma = 2 calculate iterative and noniterative gamma The next flags allow further GAMMA tuning GTHG = Calculate gamma for third harmonic generation. GEFISH = Calculate gamma for electric-field induced second harmonic generation. GIDRI = Calculate gamma for intensity dependent refractive index. GOKE = Calculate gamma for optical Kerr effect. These will be computed only if a nonzero energy (FREQ) is requested. The default for each flag is .TRUE., and they may be turned off individually by setting some .FALSE. Note however that the program determines the best way to calculate them. For example, if you wish to have the SHG results but no gamma results are needed, the SHG beta will be computed in a non-iterative way from alpha(w) and alpha(2w). However if you request the computation of the THG gamma, the second order U(w,w) results are needed and an iterative SHG calculation will be performed whether you request it or not, as it is a required intermediate. Only the following combinations make sense: INIB INIG giving FREQ(1)=0.0,0.1 e.g. w=0.1 0 0 static alpha, a(w) 1 0 static alpha,beta a(w),a(2w) noniterative b(OR), b(EOPE), b(SHG) 2 0 static alpha,beta a(w),a(2w) noniterative b(OR), b(EOPE), b(SHG) iterative b(OR), b(EOPE), b(SHG) 2 1 static alpha,beta,gamma a(w),a(2w) iterative b(OR), b(EOPE), b(SHG) noniterative g(THG), g(EFISH), g(IDRI), g(OKE) 2 2 static alpha,beta,gamma a(w),a(2w) iterative b(OR), b(EOPE), b(SHG) noniterative g(THG), g(EFISH), g(IDRI), g(OKE) iterative static gamma, g(OKE), g(THG), g(EFISH), g(IDRI), g(DC-OR) This is a quirky program: 1. INIG=2 only runs in serial, and only runs with AO integrals stored on disk. 2. ISPHER=1 may not be chosen. 3. INIB=1 and INIB=2 print the same components for OR, OPE, SHG, but different totals from the whole tensor. It is not clear which is correct. 4. units are not well specified on the output! References: for static polarizabilities, G.J.B.Hurst, M.Dupuis, E.Clementi J.Chem.Phys. 89, 385-395(1988) for dynamic polarizabilities, S.P.Karna, M.Dupuis J.Comput.Chem. 12, 487-504 (1991). P.Korambath, H.A.Kurtz, in "Nonlinear Optical Materials", ACS Symposium Series 628, S.P.Karna and A.T.Yeates, Eds. pp 133-144, Washington DC, 1996. Review: D.P.Shelton, J.E.Rice, Chem.Rev. 94, 3-29(1994). ========================================================== ==========================================================

generated on 7/7/2017