The CASINO forum

Hi Vladimir, I suspect your plots are missing the value of the c_1 parameter, which is omitted from the parameters.casl file since it is determined by the cusp condition. This is likely the main reason for the apparent difference between the two parametrizations in your plots. The following block wi...

Hi Vladimir, You can use the "plot" input block for this, which is activated by setting RUNTYPE to "plot". E.g., %block plot gjastrow_terms electron 1 spin 1 2D grid 100 100 A -1 -1 0 B 1 -1 0 C -1 1 0 fix electron 1 spin 2 @ 0.5 0.5 0 %endblock plot will plot the value of all Ja...

Hi Katharina, The difference between VMC cycles 1 and 2 has a simple explanation: if opt_method/='emin', the first cycle runs without a Jastrow factor, while the second runs with a Jastrow factor in which all free parameters are set to zero; the cusp conditions set non-free parameters to non-zero va...

Hi Katharina, This warning message is triggered by a check of the initial constraint matrix which imposes symmetries on the linear parameters in the e-e-n term. The check attempts to catch cases where the initial non-linear parameter values (i.e., cut-off lengths) may accidentally eliminate a parame...

Hi Katharina, In the first instance, yes. I assume your initial VMC cycle runs fine without a Jastrow factor, which would indicate that there is no obvious problem with the orbitals and pseudopotentials. I would recommend not using varmin at all, and using madmin in its stead. Are the cutoffs set to...

Glad that everything works : )

Best,
Pablo

Hi Katharina, Does fixing the cut-off parameters help? You can fix them without modifying the parameters files by setting OPT_NOCTF_CYCLES to the same value as OPT_CYCLES in your input file. I understand you are using OPT_METHOD=varmin. Do other optimization methods (madmin/emin) run into the same p...

Hi Vladimir, After a quick go at this molecule I get: VMC #1: E = -52.828(4) ; var = 11.0(2) (parameters.0.casl) VMC #2: E = -53.1826(7) ; var = 0.672(8) (parameters.1.casl) VMC #3: E = -53.1823(7) ; var = 0.68(1) (parameters.2.casl) VMC #4: E = -53.2012(7) ; var = 0.801(8) (parameters.3.casl) VMC #...

Hi Vladimir, Yes, you quote is a well-known result, which I was in fact making use of in my earlier reply -- E_DMC itself is independent of the Jastrow factor (it does not change the nodes of the wave function), but the better the Jastrow factor, the smaller the difference E_VMC - E_DMC, the smaller...

Hi Vladimir, How many configurations are you using for the optimization? Have you tried fixing the Jastrow cut-off values (I would expect L=3-5 a.u. to be OK values for isotropic terms in molecules)? Also, you are treating all six hydrogens as equivalent, but to me it looks like n3=n4 and n5=n6=n7=n...