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--></style></head><body lang=EN-IN link=blue vlink="#954F72" style='word-wrap:break-word'><div class=WordSection1><div><p class=MsoNormal>I am doing the optimization of a system of 51 atoms containing two dfferent types of atoms C and N using M06 functional.I used the ONCV pseudo potential for both C_ONCV_PBE-1.0.UPF and N_ONCV_PBE- 1.0 .UPF for C and N respectively.But I am getting an output with the error :<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>Error in routine C_bands<o:p></o:p></b></p></div><div><p class=MsoNormal><b>Too many bands are not converged<o:p></o:p></b></p></div><div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I changed the pseudo potential for C and N as C_ONCV_PBE-1.2.UPF and N_ONCV_PBE- 1.2.UPF . Again it shows the same error<o:p></o:p></p></div><div><div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><b>Error in routine C_bands<o:p></o:p></b></p></div><div><p class=MsoNormal><b>Too many bands are not converged<o:p></o:p></b></p></div></div><div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>What is the reason behind the problem.How can I solve this ?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks in advance<o:p></o:p></p></div></div><p class=MsoNormal><o:p> </o:p></p></div></body></html>