Masoud Nahali
masoudnahali@gmail.com
I have used "NCONV=4.5" in my input for the SCF convergence. It means that the convergence is reached when the density change between two consecutive SCF cycles is less than 10^(-4.5) or 3*10^(-5).
the lines below is one of my SCF steps :
ITER EX DEM TOTAL ENERGY E CHANGE DENSITY CHANGE DIIS ERROR INTEGRALS SKIPPED
* * * INITIATING DIIS PROCEDURE * * *
1 0 0 -3654.010061008 -3654.010061008 0.027738005 0.006150221 -1 -1
2 1 0 -3654.010871171 -0.000810163 0.023518159 0.022479261 -1 -1
3 2 0 -3654.013930379 -0.003059209 0.008856269 0.008333109 -1 -1
4 3 0 -3654.013534182 0.000396198 0.005316080 0.003565101 -1 -1
5 4 0 -3654.014225050 -0.000690868 0.001903469 0.005148299 -1 -1
6 5 0 -3654.014368343 -0.000143293 0.000956684 0.002133792 -1 -1
7 6 0 -3654.014404861 -0.000036518 0.000503151 0.000987793 -1 -1
8 7 0 -3654.014412598 -0.000007738 0.000385881 0.000328227 -1 -1
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DENSITY CONVERGED
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As it is clear 0.000385881 > 3*10^(-5) ; so why the density was converged ? Is there another criteria to reach the convergence ?
Is the "NCONV=4.5" logical when my "OPTTOL" value is 0.0001 ?
I appreciate your help in advance to understand the convergence criteria better.
Best Wishes
Masoud
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Masoud Nahali, Sharif University of Technology