Dear Q-Chem community,
I am attempting to optimize the structure of an organometallic compounds containing Zr, O, C, and H using the BP86+D3/def2-SVP method with effective core potentials (def2-ecp). Without the D3 corrections my structure converges well. With the D3 method, however, the first SCF cycle converges but the analytical gradient of the SCF energy reports “-nan” values and the optimization fails. Can anyone help me to understand why the D3 method might cause this error, and what I might do to resolve this issue? I would greatly appreciate any suggestions!
A complete input file will be required in order to diagnose this. Please use the formatted text box </> to avoid losing special characters. It is best if you can find a “minimal example” that illustrates the problem, stripping away any unnecessary keywords.
$molecule
1 1
H 0.2120610 3.2282449 3.0585973
H -2.9049710 -1.4198724 3.0723946
C 0.1770789 2.6608870 2.0963942
C -2.3935563 -1.1770121 2.1091306
O -0.9693456 2.4622594 1.5862972
O 1.2883650 2.2946394 1.6031293
O -1.6380731 -2.0712838 1.6168961
O -2.6400812 -0.0406933 1.5977379
Zr -1.6456562 1.0973507 0.0080725
Zr 1.7813494 0.8685712 0.0104477
Zr -0.1289242 -1.9876044 0.0227133
O 0.0031180 -0.0058661 0.7124107
O 0.1196316 1.7603047 -1.0663431
H 0.1754953 2.4825208 -1.7146750
O -1.5865918 -0.7956702 -1.0521337
H -2.2227191 -1.1138609 -1.7147017
C -2.9194207 1.9936849 -2.0150017
C -2.6055122 3.1362900 -1.2163871
C -3.3442929 3.0427473 0.0004953
C -4.1175944 1.8477699 -0.0433548
C -3.8586010 1.2003343 -1.2875894
O 1.4890124 -1.0022862 -1.0450477
H 2.0774711 -1.3964367 -1.7111739
O 2.6138249 -0.3879645 1.6081907
C 3.1489666 1.6161845 -2.0124468
C 3.9876469 0.7069928 -1.2976805
C 4.3293935 1.3064488 -0.0489312
C 3.7089346 2.5867812 0.0094411
C 2.9809620 2.7808761 -1.2011479
O 1.3538384 -2.2697734 1.6131813
C -0.2121088 -3.5436645 -1.9938685
C -1.4042990 -3.8105268 -1.2530790
C -1.0312414 -4.4092554 -0.0130414
C 0.3884775 -4.5183109 0.0145398
C 0.8960168 -3.9865998 -1.2074801
H -2.5336375 1.7801114 -3.0213500
H -1.9384869 3.9631153 -1.4964567
H -3.3103545 3.7578311 0.8319065
H -4.7853186 1.4840494 0.7475047
H -4.3327001 0.2714939 -1.6332598
C 2.2202794 -1.4855464 2.1110846
H 2.7366948 1.4605369 -3.0189906
H 4.3396693 -0.2708035 -1.6541183
H 4.9527209 0.8569050 0.7340689
H 3.7676840 3.2927388 0.8473018
H 2.4184058 3.6857715 -1.4682778
H -0.1602128 -3.1093455 -3.0018594
H -2.4341631 -3.6214516 -1.5857619
H -1.7157869 -4.7172482 0.7870857
H 0.9867424 -4.9283429 0.8378938
H 1.9547065 -3.9574768 -1.4990952
H 2.6948858 -1.8008840 3.0721471
$end
$rem
BASIS = def2-SVP
ECP = def2-ecp
JOB_TYPE = Optimization
METHOD = BP86
DFT_D = D3
$end
Thank you for your help! I have confirmed that the above minimal example causes the same issue–the SCF energy gradient gives all “-nan” values.
Hi Ari,
(1) I can reproduce this error with the latest version of Q-Chem (pre-release v. 6.3).
(2) It appears to be problem with the dispersion correction, because commenting out DFT_D removes the problem.
(3) It’s specifically a problem for Zr, because replacing Zr with Ti removes the problem.
(3) Those changes isolate the problem but it’s not what you want. As a workaround, I found that DFT_D = D4 seems to work (at least through one optimization step, no NaN).
I will submit a bug ticket about D3 (which affects both the D3(0) and D3(BJ) versions, I checked both).
I just checked and the D4 method worked well. Thank you for helping with this!