CCL: Gaussian job keeps giving Rare condition:small coef for last iteration



 Sent to CCL by: Herbert Fruchtl [herbert.fruchtl:st-andrews.ac.uk]
 You can try to add XQC to the list of keywords inside your "scf="
 list.
 
With ionic fragments you should also be careful about charges and multiplicities. I haven't looked at those in your input.
   Herbert
 
On 20/12/2020 02:24, KamalEldeen Sobhy Nassar s-kamalsobhy ~ zewailcity.edu.eg wrote:
 Sent to CCL by: "KamalEldeen Sobhy Nassar"
 [s-kamalsobhy!=!zewailcity.edu.eg]
 Hi! I'm kind of beginner in the field of computational chemistry and I'm
 trying to optimize a system of copper ion with graphitic carbon nitride
 quantum dot. the job converged at hartree fock level of theory but failed
 to converge at DFT giving me this in the output file
 " EnCoef did   100 forward-backward iterations
   EnCoef did     4 forward-backward iterations
   EnCoef did     9 forward-backward iterations
   EnCoef did     4 forward-backward iterations
   EnCoef did     5 forward-backward iterations
   EnCoef did     5 forward-backward iterations
   EnCoef did     5 forward-backward iterations
   EnCoef did    10 forward-backward iterations
   EnCoef did     4 forward-backward iterations
   EnCoef did     5 forward-backward iterations
   EnCoef did     2 forward-backward iterations
   EnCoef did     3 forward-backward iterations
   EnCoef did     5 forward-backward iterations
   EnCoef did     3 forward-backward iterations
   EnCoef did     5 forward-backward iterations
   EnCoef did     8 forward-backward iterations
   EnCoef did     8 forward-backward iterations
   EnCoef did     8 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did     6 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration:  0.112D-14
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration: -0.926D-15
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration:  0.453D-15
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration:  0.103D-14
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration: -0.433D-15
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration:  0.112D-14
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration:  0.157D-14
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   Rare condition: small coef for last iteration: -0.343D-14
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations
   EnCoef did   100 forward-backward iterations"
 my input file is
 # opt M06/genECP Geom=Connectivity int=ultrafine
 scf=(tight,noincfock,novaracc,maxcycle=150)
 Required
 2 2 0 1 2 2
   N(Fragment=1)         -3.32051400    1.18371200   -0.45017600
   N(Fragment=1)         -3.32236500   -1.17853000   -0.45018000
   N(Fragment=1)         -1.55877100    0.00121000    0.47102300
   N(Fragment=1)         -1.34767900    2.31985300    0.10084500
   N(Fragment=1)          0.62809300    3.45015200   -0.41917300
   N(Fragment=1)          0.76877200    1.32268900    0.48160900
   N(Fragment=1)          2.67569700    2.27598300   -0.42329700
   N(Fragment=1)         -1.35130200   -2.31774800    0.10084300
   N(Fragment=1)          0.76669100   -1.32385900    0.48162300
   N(Fragment=1)          0.62271500   -3.45110900   -0.41914700
   N(Fragment=1)          2.67213800   -2.28012300   -0.42326600
   N(Fragment=1)          2.68524800   -0.00208000    0.09950000
   N(Fragment=1)          4.56099000   -0.00355200   -1.33458600
   N(Fragment=1)          4.84528600   -0.00377300    0.99031000
   N(Fragment=1)          6.71434700   -0.00523600   -0.41743600
   C(Fragment=1)         -3.93027200    0.00307000   -0.61021700
   C(Fragment=1)         -2.10364300    1.15330400    0.04686100
   C(Fragment=1)         -2.10545100   -1.15002400    0.04685900
   C(Fragment=1)          0.03790500    2.37687100    0.05972700
   C(Fragment=1)          1.95506100    3.39391100   -0.57225400
   C(Fragment=1)          2.04577100    1.22887400    0.05810700
   C(Fragment=1)          0.03418800   -2.37691300    0.05973800
   C(Fragment=1)          2.04384400   -1.23202500    0.05812100
   C(Fragment=1)          1.94976900   -3.39693100   -0.57221600
   C(Fragment=1)          4.11865100   -0.00320500   -0.10140700
   C(Fragment=1)          5.89163100   -0.00459300   -1.46280200
   C(Fragment=1)          6.17110700   -0.00481000    0.79312500
   C(Fragment=1)         -2.05748100    3.56643700   -0.09143500
   N(Fragment=1)         -2.27902000    3.95956000   -1.32153900
   N(Fragment=1)         -2.41709100    4.18980500    1.00516100
   C(Fragment=1)         -2.94049100    5.11493700   -1.44056800
   C(Fragment=1)         -3.07603000    5.34174600    0.81698700
   N(Fragment=1)         -3.34785400    5.82174100   -0.38970300
   C(Fragment=1)         -2.06303700   -3.56322800   -0.09144700
   N(Fragment=1)         -2.28518100   -3.95599900   -1.32155400
   N(Fragment=1)         -2.42362000   -4.18604300    1.00514400
   C(Fragment=1)         -2.94844600   -5.11034500   -1.44059300
   C(Fragment=1)         -3.08434800   -5.33695700    0.81696000
   N(Fragment=1)         -3.35691200   -5.81652200   -0.38973500
   H(Fragment=1)          6.81215200   -0.00531200    1.64485000
   H(Fragment=1)          6.30898700   -0.00492000   -2.44360500
   H(Fragment=1)         -3.39316800    5.89213500    1.67307600
   H(Fragment=1)         -3.14934300    5.48400000   -2.41849400
   H(Fragment=1)         -3.15786700   -5.47907700   -2.41852300
   H(Fragment=1)         -3.40234400   -5.88685900    1.67304400
   H(Fragment=1)          2.46356500    4.28188600   -0.87525300
   H(Fragment=1)         -4.94867100    0.00386800   -0.92891600
   H(Fragment=1)          2.45689700   -4.28569900   -0.87520000
   Cu(Fragment=2)         0.02999100   -0.00005700    1.65151200
   1 16 1.5 17 2.0
   2 16 1.5 18 2.0
   3 17 1.5 18 1.5 49 1.0
   4 17 1.0 19 1.0 28 1.0
   5 19 2.0 20 1.5
   6 19 1.5 21 1.5 49 1.0
   7 20 1.5 21 2.0
   8 18 1.0 22 1.0 34 1.0
   9 22 1.5 23 1.5 49 1.0
   10 22 2.0 24 1.5
   11 23 2.0 24 1.5
   12 21 1.0 23 1.0 25 1.0
   13 25 2.0 26 1.5
   14 25 2.0 27 1.5
   15 26 1.5 27 1.5
   16 47 1.0
   17
   18
   19
   20 46 1.0
   21
   22
   23
   24 48 1.0
   25
   26 41 1.0
   27 40 1.0
   28 29 2.0 30 2.0
   29 31 1.5
   30 32 1.5
   31 33 1.5 43 1.0
   32 33 1.5 42 1.0
   33
   34 35 2.0 36 2.0
   35 37 1.5
   36 38 1.5
   37 39 1.5 44 1.0
   38 39 1.5 45 1.0
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
 H C N
 6-31+g*
 ****
 Cu 0
 SDD
 ****
 Cu 0
 SDD
 please can anyone help me with this because I've been trying to solve it
 
for days!>
 --
 Herbert Fruchtl
 Senior Scientific Computing Officer / HPC Administrator
 School of Chemistry, IT Services
 University of St Andrews
 --
 The University of St Andrews is a charity registered in Scotland:
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