The density matrix tolerance is set to the 5th decimal place. If you find the write statement in the code that prints the SCF line, you can then change the format specifier to print out another decimal place. The DM tolerance should be changing.
One way to tell your DM tolerance is changing is that the total energy is changing and hence your density matrix is changing. eg. -3416.0958 to -3416.0959 eV. on steps 57 - 58. In these situations, I have luck using a mixing weight of 0.001. You might want to lower the number of density matrices used to mix for the next step. Maybe Broyden mixing? Thanks Burak ----- Original Message ----- From: Postnikov Andrei <emandreipostni...@gmail.com> Date: Friday, June 25, 2010 2:19 pm Subject: [SIESTA-L] the SC problem To: siesta-l@uam.es > Dear All, > > In my SC calculation, there are always many sc steps like these: > > siesta: 34 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 35 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 36 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 37 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 38 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 39 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 40 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 41 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 42 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 43 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 44 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 45 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 46 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 47 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 48 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 49 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 50 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 51 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 52 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 53 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 54 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 55 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 56 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 57 -3416.0640 -3416.0639 -3416.0958 0.0000 -3.9995 > siesta: 58 -3416.0640 -3416.0640 -3416.0959 0.0000 -3.9995 > siesta: 59 -3416.0640 -3416.0640 -3416.0959 0.0000 -3.9995 > siesta: 60 -3416.0640 -3416.0640 -3416.0959 0.0000 -3.9995 > siesta: 61 -3416.0640 -3416.0640 -3416.0959 0.0000 -3.9995 > siesta: 62 -3416.0640 -3416.0640 -3416.0959 0.0000 -3.9995 > > I am confused that the dDmax is zero in so many steps. However, it > doest not > reach convergence. Why? > > I use the following DM paramteters: > > DM.MixingWeight 0.05 > DM.Tolerance 1.d-5 > DM.NumberPulay 6 UTS CRICOS Provider Code: 00099F DISCLAIMER: This email message and any accompanying attachments may contain confidential information. If you are not the intended recipient, do not read, use, disseminate, distribute or copy this message or attachments. If you have received this message in error, please notify the sender immediately and delete this message. Any views expressed in this message are those of the individual sender, except where the sender expressly, and with authority, states them to be the views of the University of Technology Sydney. Before opening any attachments, please check them for viruses and defects. Think. Green. Do. Please consider the environment before printing this email.
