[Pw_forum] problem with diagonalization scheme

[Raghani Pushpa]

dear users,
i was performing the structural optimization for a cluster by using the
davidson diagonalization scheme. but the following error came

     iteration # 21     ecut=    20.00 ryd     beta=0.50
     Davidson diagonalization with overlap
   WARNING:    29 eigenvalues not converged
   WARNING:    26 eigenvalues not converged
   WARNING:    28 eigenvalues not converged
   WARNING:    40 eigenvalues not converged
   WARNING:    28 eigenvalues not converged
   WARNING:    28 eigenvalues not converged
 warning :  28 eigenvectors not converged after   6 attemps

 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from c_bands : error #         1
     too many bands are not converged
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     stopping ...

then started using the conjugate gradient diagonalization scheme and the
error comes as
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     from c_bands : error #         1
     CG and DIIS diagonalization not implemented
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     stopping ...

is it really true that the conjugate gradient scheme has not been
implemented? what should i do to solve this problem?

pushpa