<div dir="ltr">Hello, everyone, I am using the cp2k qmmm to optimize the structure of Pt6 supported on Al2O3 surface. But I encounter a problem about the convergence of the qmmm. 1) Firstly, the scf of the QM part converges strangely like this: All of the QM SCF converges within two steps, and the second number in the Covergence column is always zero. Step Update method Time Convergence Total energy Change ------------------------------------------------------------------------------ 1 Broy./Dav. 0.40E+00 4.1 2.02291583 -81.2822944519 -8.13E+01 2 Broy./Dav. 0.40E+00 5.8 0.0000E+00 -70.8618426104 1.04E+01 *** SCF run converged in 2 steps *** 2) Then, the convergence for the structure is also strange. I want the max force is below 0.05 eV/A, so I use something like this &GEO_OPT MAX_ITER 20 OPTIMIZER LBFGS MAX_FORCE [eV*angstrom^-1] 0.05 &END GEO_OPT But fininally, the program ends "normally" with this massage (shown below). Obviously, In the previous Convergence check, the maxforce is larger Than what I want. Convergence check : Max. step size = 0.0000000000 Conv. limit for step size = 0.0030000000 Convergence in step size = YES RMS step size = 0.0000000000 Conv. limit for RMS step = 0.0015000000 Convergence in RMS step = YES Max. gradient = 0.5334857508 Conv. limit for gradients = 0.0009723453 Conv. for gradients = NO RMS gradient = 0.0328663882 Conv. limit for RMS grad. = 0.0003000000 Conv. for gradients = NO --------------------------------------------------- -------------------------- OPTIMIZATION STEP: 2 -------------------------- *********************************************** * Specific L-BFGS convergence criteria * WANTED_PROJ_GRADIENT and WANTED_REL_F_ERROR * satisfied .... run CONVERGED! *********************************************** So, what is the source of this error in my calculation. Thank you for any advice ! The input files and the input structure is in the attachment. Geng Sun </div>