:orphan: Atomic start guess ================== Initial SCF run --------------- We consider the Hartree-Fock calculation of plutonium dioxide cluster .. image:: Pucluster.jpg :scale: 80 :alt: Plutonium dioxide cluster In order to help convergence we will employ an atomic start. Preparing the atomic start -------------------------- For each atom we run a SCF calculation in full (linear) symmetry based on the atomic ground state configuration. For open-shell atoms this amounts to an average-of-configuration (AOC) calculation at the HF level, and a fractional occupation calculation at the DFT level. Hydrogen atom ~~~~~~~~~~~~~ We run the hydrogen atom as a one-electron system. The input file ``H.inp`` accordingly reads: :: **DIRAC .WAVE FUNCTION .ANALYZE **GENERAL .ACMOUT **HAMILTONIAN .ONESYS **WAVE FUNCTIONS .SCF *SCF .CLOSED SHELL 2 0 **ANALYZE .MULPOP *END OF The molecular input ``H.mol`` is :: BASIS C 1 A 1. 1 H 0.0000000000 0.0000000000 0.0000000000 LARGE BASIS cc-pVDZ FINISH We run pam :: pam --inp=H.inp --mol=H.mol --get=ACMOUT mv DFACMO ac.H Oxygen atom ~~~~~~~~~~~ The input file ``O.inp`` reads: :: **DIRAC .WAVE FUNCTION .ANALYZE **GENERAL .ACMOUT **WAVE FUNCTIONS .SCF *SCF .CLOSED SHELL 4 0 .OPEN SHELL 1 4/0,6 **ANALYZE .MULPOP *END OF The molecular input ``O.mol`` is :: BASIS C 1 A 8. 1 O 0.0000000000 0.0000000000 0.0000000000 LARGE BASIS cc-pVDZ FINISH We run the calculation :: pam --inp=O.inp --mol=O.mol --get=DFACMO mv DFACMO ac.O Plutonium atom ~~~~~~~~~~~~~~ For plutonium we employ the :math:`[Rn]5f^4` configuration of the :math:`Pu^{4+}` cation. The input file ``Pu.inp`` accordingly reads: :: **DIRAC .WAVE FUNCTION .ANALYZE **GENERAL .ACMOUT **WAVE FUNCTIONS .SCF *SCF .CLOSED SHELL 42 44 .OPEN SHELL 1 4/0,14 **INTEGRALS *READIN .UNCONTRACT **ANALYZE .MULPOP *END OF The molecular file 'Pu.mol' reads :: BASIS C 1 A 94. 1 Pu 0.0000000000 0.0000000000 0.0000000000 LARGE BASIS dyall.v2z FINISH We run the calculation :: pam --inp=Pu.inp --mol=Pu.mol --get=DFACMO mv DFACMO ac.Pu Running the atomic start ------------------------ We are now ready to run the atomic start. The input file 'PuO2.inp' reads:: **DIRAC .WAVE FUNC .ANALYZE #.INPTES **WAVE FUN .SCF *SCF .ATOMST AFPUXX 2 1..43 1.00 44..50 0.286 AFOXXX 2 1,2 1.00 3..5 0.667 AFHXXX 1 1 0.50 .CLOSED SHELL 84 86 **ANALYZE .MULPOP **END OF The keyword ``ATOMST`` is followed by input for each atomic type. The occupations chosen corresponds to those of the atomic runs, but the user may modify this at will. Please note that the order of atoms corresponds to the order they appear in the molecule file. The molecular input file 'PuO2.mol' reads:: DIRAC C 3 0 A 94. 1 Pu 0.0000000000 0.0000000000 0.0000000000 LARGE BASIS dyall.v2z 8. 8 O 1.3490000000 1.3490000000 1.3490000000 O 1.3490000000 1.3490000000 -1.3490000000 O -1.3490000000 1.3490000000 1.3490000000 O -1.3490000000 1.3490000000 -1.3490000000 O 1.3490000000 -1.3490000000 1.3490000000 O 1.3490000000 -1.3490000000 -1.3490000000 O -1.3490000000 -1.3490000000 1.3490000000 O -1.3490000000 -1.3490000000 -1.3490000000 LARGE BASIS cc-pVDZ 0.5 24 H 1.9263502692 0.7716497308 1.9263502692 H 1.9263502692 0.7716497308 -1.9263502692 H -1.9263502692 0.7716497308 1.9263502692 H -1.9263502692 0.7716497308 -1.9263502692 H 1.9263502692 -0.7716497308 1.9263502692 H 1.9263502692 -0.7716497308 -1.9263502692 H -1.9263502692 -0.7716497308 1.9263502692 H -1.9263502692 -0.7716497308 -1.9263502692 H 1.9263502692 1.9263502692 0.7716497308 H 1.9263502692 1.9263502692 -0.7716497308 H -1.9263502692 1.9263502692 0.7716497308 H -1.9263502692 1.9263502692 -0.7716497308 H 1.9263502692 -1.9263502692 0.7716497308 H 1.9263502692 -1.9263502692 -0.7716497308 H -1.9263502692 -1.9263502692 0.7716497308 H -1.9263502692 -1.9263502692 -0.7716497308 H 0.7716497308 1.9263502692 1.9263502692 H 0.7716497308 1.9263502692 -1.9263502692 H -0.7716497308 1.9263502692 1.9263502692 H -0.7716497308 1.9263502692 -1.9263502692 H 0.7716497308 -1.9263502692 1.9263502692 H 0.7716497308 -1.9263502692 -1.9263502692 H -0.7716497308 -1.9263502692 1.9263502692 H -0.7716497308 -1.9263502692 -1.9263502692 LARGE BASIS cc-pVDZ #SMALL KINBAL FINISH Before running the calculation the user must make provide links to the atomic coefficient files :: ln -s ac.Pu AFPUXX ln -s ac.C AFCXXX ln -s ac.H AFHXXX and the calculation was then run as :: pam --mol=PuO2.mol --inp=PuO2.inp --copy="AF*" --outcmo --mw=105 --mpi=32 This calculation converges smoothly after 9 iterations :: SCF - CYCLE ----------- * Convergence on norm of error vector (gradient). Desired convergence:1.000D-07 Allowed convergence:1.000D-06 * ERGVAL - convergence in total energy * FCKVAL - convergence in maximum change in total Fock matrix * EVCVAL - convergence in error vector (gradient) -------------------------------------------------------------------------------------------------------------------------------- Energy ERGVAL FCKVAL EVCVAL Conv.acc CPU Integrals Time stamp -------------------------------------------------------------------------------------------------------------------------------- It. 1 -30262.16062810 3.03D+04 0.00D+00 0.00D+00 Atomic s 8min27.160s LL SL Sun Dec 2 It. 2 -29246.11569530 -1.02D+03 -4.18D+01 1.15D+01 18min50.650s LL SL Sun Dec 2 It. 3 -29248.64080628 2.53D+00 4.35D+00 5.49D+00 DIIS 2 18min31.760s LL SL Mon Dec 3 It. 4 -29248.86829228 2.27D-01 -1.32D+00 2.81D-01 DIIS 3 17min35.410s LL SL Mon Dec 3 It. 5 -29248.86879546 5.03D-04 3.32D-02 3.76D-02 DIIS 4 16min51.240s LL SL Mon Dec 3 It. 6 -29248.86880842 1.30D-05 8.21D-03 8.29D-04 DIIS 5 15min15.820s LL SL Mon Dec 3 It. 7 -29248.86880842 3.88D-09 -5.99D-05 5.49D-05 DIIS 6 13min26.070s LL SL Mon Dec 3 It. 8 -29248.86880843 3.43D-09 8.30D-06 1.55D-06 DIIS 7 11min31.390s LL SL Mon Dec 3 It. 9 -29248.86880842 -7.49D-10 -1.04D-06 4.71D-08 DIIS 7 9min 3.550s LL SL Mon Dec 3 --------------------------------------------------------------------------------------------------------------------------------