Quickstep: SCF Energy increasing after few outer-SCF cycles
Sharma SRK Chaitanya Yamijala
sharma... at gmail.com
Wed Aug 21 13:54:12 UTC 2013
Dear all CP2K users,
I am trying to optimize a Graphene Quantum Dot using BLYP-DFT-D3/DZVP
method as implemented in CP2K. While optimizing I have observed that, SCF
energy is decreasing (i.e. becoming more negative) at the beginning of the
run, but after few outer-SCF loops, the energy starts increasing and the
increment is going on and on if I am leaving the system to run.
Also, I have observed that the inner-SCF energy has reached a convergence
(for this system) value of ~ 10^(-5) after 2 outer-SCF cycles (where my
EPS_SCF is 1.0E-6) and after the beginning of the 3rd outer-SCF tolerance
has increased to a value of ~ 10^(-3).
I would like to get your suggestions on any way to avoid this convergence
issue. The input file and the output file (just before and after the 2nd
outer-SCF) are given below (hopping they may be help you in suggesting).
Thank you all,
Sincerely,
Sharma.
P.S: I have checked in the mailing list but I couldn't exactly found any
post on this issue (though there are on BOMD-energy increment etc.)
*Input_file:*
&FORCE_EVAL
METHOD Quickstep
&DFT
CHARGE = 0
MULTIPLICITY = 2
LSD # for odd number of electrons and specifying this keyword itself
enforces for spin-polarized calculations
BASIS_SET_FILE_NAME BASIS_MOLOPT
POTENTIAL_FILE_NAME GTH_POTENTIALS
&MGRID
CUTOFF 320
NGRIDS 5
REL_CUTOFF 40
&END MGRID
&QS
METHOD GPW
EPS_DEFAULT 1.0E-10
&END QS
&SCF
SCF_GUESS RESTART
EPS_SCF 1.0E-6
MAX_SCF 100
&OUTER_SCF
EPS_SCF 1.0E-6
MAX_SCF 500
&END
&OT
MINIMIZER CG
PRECONDITIONER FULL_ALL
ENERGY_GAP 0.001
STEPSIZE 0.05
&END
&END SCF
&XC
&XC_FUNCTIONAL BLYP
&END XC_FUNCTIONAL
&XC_GRID
XC_DERIV SPLINE2
XC_SMOOTH_RHO NN50
&END XC_GRID
&vdW_POTENTIAL
DISPERSION_FUNCTIONAL PAIR_POTENTIAL # POTENTIAL_TYPE is alias to
DISPERSION_FUNCTIONAL
&PAIR_POTENTIAL
TYPE DFTD3
PARAMETER_FILE_NAME dftd3.dat
REFERENCE_FUNCTIONAL BLYP
&END PAIR_POTENTIAL
&END vdW_POTENTIAL
&END XC
&POISSON
POISSON_SOLVER WAVELET
PERIODIC NONE
&END POISSON
&END DFT
&SUBSYS
&CELL
ABC 38.0 38.0 38.0
ALPHA_BETA_GAMMA 90.0 90.0 90.00
PERIODIC NONE
&END CELL
&TOPOLOGY
&CENTER_COORDINATES
&END
&END
&COORD
@INCLUDE gqd_270.xyz
&END COORD
&KIND H
BASIS_SET DZVP-MOLOPT-SR-GTH
POTENTIAL GTH-BLYP-q1
&END KIND
&KIND C
BASIS_SET DZVP-MOLOPT-SR-GTH
POTENTIAL GTH-BLYP-q4
&END KIND
&KIND N
BASIS_SET DZVP-MOLOPT-SR-GTH
POTENTIAL GTH-BLYP-q5
&END KIND
&END SUBSYS
&END FORCE_EVAL
&GLOBAL
PROJECT au20_tetra_on_n-gqd
RUN_TYPE GEO_OPT
PRINT_LEVEL MEDIUM
&END GLOBAL
&MOTION
&GEO_OPT
OPTIMIZER BFGS
MAX_ITER 5000
MAX_FORCE 1.00D-4
TYPE MINIMIZATION
&END
&END MOTION
###########################################################################################################################
*
*
*OUTPUT-FILE:*
98 OT LS 0.54E-01 6.9 -1982.8376246687
Trace(PS): 1174.9999638412
Electronic density on regular grids: -1174.9999638398
0.0000361602
Core density on regular grids: 1174.9999998887
-0.0000001113
Total charge density on r-space grids: 0.0000360489
Total charge density g-space grids: 0.0000360489
99 OT CG 0.54E-01 12.3 0.00000845 -1982.8383595833
-7.61E-05
Trace(PS): 1174.9999635922
Electronic density on regular grids: -1174.9999635907
0.0000364093
Core density on regular grids: 1174.9999998887
-0.0000001113
Total charge density on r-space grids: 0.0000362980
Total charge density g-space grids: 0.0000362980
100 OT LS 0.22E+00 6.9 -1982.8383813757
*** SCF run NOT converged ***
Electronic density on regular grids: -1174.9999635907
0.0000364093
Core density on regular grids: 1174.9999998887
-0.0000001113
Total charge density on r-space grids: 0.0000362980
Total charge density g-space grids: 0.0000362980
Overlap energy of the core charge distribution:
0.00005046108667
Self energy of the core charge distribution:
-4271.91259980407449
Core Hamiltonian energy:
1351.88408937624945
Hartree energy:
1448.17384258600623
Exchange-correlation energy:
-510.06161737575133
Dispersion energy:
-0.92214661917833
Total energy:
-1982.83838137566136
outer SCF iter = 3 RMS gradient = 0.84E-05 energy =
-1982.8383813757
----------------------------------- OT
---------------------------------------
Allowing for rotations: F
Optimizing orbital energies: F
Minimizer : CG : conjugate gradient
Preconditioner : FULL_ALL : diagonalization, state selective
Precond_solver : DEFAULT
Line search : 2PNT : 2 energies, one gradient
stepsize : 0.05000000
energy_gap : 0.00100000
eps_taylor : 0.10000E-15
max_taylor : 4
mixed_precision : F
----------------------------------- OT
---------------------------------------
Step Update method Time Convergence Total energy
Change
------------------------------------------------------------------------------
Trace(PS): 1174.9999628452
Electronic density on regular grids: -1174.9999628438
0.0000371562
Core density on regular grids: 1174.9999998887
-0.0000001113
Total charge density on r-space grids: 0.0000370449
Total charge density g-space grids: 0.0000370449
1 OT CG 0.50E-01 24.7 0.00073898 -1982.8383578477
1.74E-06
Trace(PS): 1174.6089204778
Electronic density on regular grids: -1174.6089204763
0.3910795237
Core density on regular grids: 1174.9999998887
-0.0000001113
Total charge density on r-space grids: 0.3910794124
Total charge density g-space grids: 0.3910794124
2 OT LS 0.16E-01 6.8 -1982.7669389193
Trace(PS): 1174.8781005916
Electronic density on regular grids: -1174.8781005901
0.1218994099
Core density on regular grids: 1174.9999998887
-0.0000001113
Total charge density on r-space grids: 0.1218992986
Total charge density g-space grids: 0.1218992986
3 OT CG 0.16E-01 12.3 0.00075231 -1982.7595972134
7.88E-02
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