Hi,

I started the same input file doing a geometry optimization twice. One of the two geometry optimizations completed in 28 cycles the other failed after 50 cycles. Is this expected? I could imagine that there is some randomness in the initialization of the hessian matrix, is there a better way?

Below is the input file.

Thanks!

Alberto

optMethod = 'hf' optBasis = '6-311g*' finalMethod = 'mp2' finalBasis = 'aug-cc-pv[dt]z' import time t1 = time.time() def saveFile(name, string): f=open(name,'w') f.write(string) f.close() molecule rec0000004 { 0 1 C 19.421000 44.630001 30.513000 C 20.502001 45.252998 29.702999 C 20.663000 43.862999 30.209999 C 20.482000 42.773998 29.070999 O 19.398001 42.680000 28.385000 N 21.586000 41.832001 28.763000 C 21.386000 40.847000 27.728001 C 21.709999 39.511002 28.292000 C 22.889999 41.744999 29.422001 C 23.785999 40.590000 29.018999 N 23.125000 39.403999 28.490000 C 23.771999 38.130001 28.141001 O 23.066000 37.231998 27.705999 C 25.247999 37.744999 28.232000 C 25.604000 36.754002 29.219000 C 26.160000 38.056000 27.202999 F 25.826000 38.933998 26.233000 C 27.476999 37.537998 27.212999 C 27.827999 36.626999 28.232000 C 26.872999 36.250999 29.233000 C 27.319000 35.233002 30.304001 C 26.165001 34.379002 30.886000 C 25.993999 32.953999 30.659000 C 26.878000 32.198002 29.760000 C 26.622999 30.834999 29.514999 C 25.556999 30.184000 30.177000 C 24.684000 30.896999 31.062000 C 24.934000 32.291000 31.320000 C 24.100000 33.037998 32.240002 O 23.179001 32.527000 32.881001 N 24.285999 34.365002 32.410000 N 25.365000 34.993999 31.766001 H 19.228201 44.982498 31.537001 H 18.470200 44.347698 30.037300 H 20.350000 45.431900 28.628300 H 21.107901 46.066700 30.128099 H 21.385500 43.652599 31.012400 H 20.338499 40.866001 27.392900 H 22.047501 41.062199 26.875900 H 21.194799 39.385601 29.255800 H 21.377701 38.728401 27.594000 H 23.433201 42.677299 29.208401 H 22.710800 41.664700 30.504299 H 24.478100 40.958302 28.247400 H 24.357100 40.284901 29.908300 H 24.874201 36.414001 29.938900 H 28.194201 37.832001 26.460899 H 28.823799 36.209801 28.257999 H 28.055599 34.554100 29.849501 H 27.790400 35.785400 31.130301 H 27.719000 32.685699 29.289700 H 27.242300 30.286501 28.820801 H 25.397400 29.128599 30.012600 H 23.849600 30.395100 31.529200 H 23.663401 34.893398 32.987202 no_com no_reorient } memory 8 Gb set basis $optBasis set opt_coordinates cartesian set optking dynamic_level 1 optE, optWfn = optimize(optMethod, return_wfn=True) t2 = time.time() set basis $finalBasis