problem converging molecule in doublet state
garold
g.murd... at gmail.com
Fri Apr 8 03:03:30 UTC 2011
Dear CP2K Community,
I am attempting to calculate the energy of a molecule (dicarboyxlate
anion with a lithium cation; net charge is zero) in its doublet
state. I have tried using both restricted and unrestricted formalisms
(LSD and ROKS, respectively). However, I cannot get the SCF to
converge with either. I have been using both B3LYP and BLYP and
various basis sets. Ideally, I would prefer to use B3LYP/GAPW/6-31+G*
but have been unable to obtain convergence even with BLYP/GAPW/6-31G*
(no diffuse functions) or BLYP/GPW/DZVP-MOLOPT-SR-GTH (my original
assumption was that diffuse functions were source of the problem).
The input for my preferred method/basis set is below and the output is
attached. Please let me know if you have any suggestions. Thank you
in advance.
Note that I am using a recent tested version of cp2k compiled with
libint. Both BLYP/ and B3LYP/GAPW/6-31+G* work well for the closed-
shell, singlet version of this system (e.g., with one electron added,
net charge of -1, same geometry). However, a preconditioner (OT/
OUTER_SCF option) does not seem to work well for this system so I am
not using it.
Best regards,
Garold Murdachaew
ps: Input file (gzipped output file is attached):
&FORCE_EVAL
METHOD Quickstep
&DFT
LSD
CHARGE 0
MULTIPLICITY 2
BASIS_SET_FILE_NAME ../EMSL_BASIS_SETS_mine
POTENTIAL_FILE_NAME ../POTENTIAL
&MGRID
CUTOFF 280
NGRIDS 5
&END MGRID
&QS
METHOD GAPW
&END QS
&POISSON
PERIODIC NONE
PSOLVER MT
&END
&SCF
SCF_GUESS ATOMIC
EPS_SCF 1.0E-7
MAX_SCF 20
! &OUTER_SCF
! EPS_SCF 1.0E-7
! MAX_SCF 20
! &END
! &OT
! PRECONDITIONER FULL_ALL
! &END
&END SCF
&XC
&XC_FUNCTIONAL
&LYP
SCALE_C 0.81
&END
&BECKE88
SCALE_X 0.72
&END
&VWN
FUNCTIONAL_TYPE VWN3
SCALE_C 0.19
&END
&XALPHA
SCALE_X 0.08
&END
&END XC_FUNCTIONAL
&HF
&SCREENING
EPS_SCHWARZ 1.0E-10
&END
&MEMORY
MAX_MEMORY 1200
&END
FRACTION 0.20
&END
&END XC
&END DFT
&SUBSYS
&CELL
ABC 20.0 20.0 20.0
PERIODIC NONE
&END CELL
&COORD
C -0.793023 -0.703538 0.527367
C -0.046767 -0.838845 -0.834379
C -0.109334 0.381305 -1.793731
O -0.533605 0.203716 -2.940264
C 0.080655 -0.434112 1.783207
O -0.014088 -1.209796 2.739982
O 0.835715 0.609771 1.736225
O 0.313892 1.501426 -1.316006
H -1.529788 0.107036 0.458189
H -1.351096 -1.620668 0.723529
H 1.012459 -1.057227 -0.647331
H -0.452088 -1.690968 -1.382698
Li 0.909030 1.669426 0.332287
&END COORD
&KIND C
BASIS_SET 6-31+Gx
POTENTIAL ALL
&END KIND
&KIND O
BASIS_SET 6-31+Gx
POTENTIAL ALL
&END KIND
&KIND H
BASIS_SET 6-31Gx
POTENTIAL ALL
&END KIND
&KIND Li
BASIS_SET 6-31+Gx
POTENTIAL ALL
&END KIND
&END SUBSYS
&END FORCE_EVAL
&GLOBAL
PROJECT d_m
PRINT_LEVEL MEDIUM
&END GLOBAL
pps: I constructed the 6-31+G* basis set simply by adding the diffuse
functions to C, O, and Li, the basis set file is attached.
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