I am trying to run EPW on my 2D system. But after doing phonon and all steps, in the epw step error appeared. The error is given below;

**Calculating kgmap**

Progress kgmap: ########################################

kmaps : 0.37s CPU 1.15s WALL ( 1 calls)

Symmetries of Bravais lattice: 24

Symmetries of crystal: 12

===================================================================

irreducible q point # 1

===================================================================

Symmetries of small group of q: 12

in addition sym. q -> -q+G:

Number of q in the star = 1

List of q in the star:

1 0.000000000 0.000000000 0.000000000

Imposing acoustic sum rule on the dynamical matrix

q( 1 ) = ( 0.0000000 0.0000000 0.0000000 )

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Error in routine readdvscf (80):

../0p_ph1/save/Sb0p.dvscf_q1 too short, check ecut

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Progress kgmap: ########################################

kmaps : 0.37s CPU 1.15s WALL ( 1 calls)

Symmetries of Bravais lattice: 24

Symmetries of crystal: 12

===================================================================

irreducible q point # 1

===================================================================

Symmetries of small group of q: 12

in addition sym. q -> -q+G:

Number of q in the star = 1

List of q in the star:

1 0.000000000 0.000000000 0.000000000

Imposing acoustic sum rule on the dynamical matrix

q( 1 ) = ( 0.0000000 0.0000000 0.0000000 )

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Error in routine readdvscf (80):

../0p_ph1/save/Sb0p.dvscf_q1 too short, check ecut

%%

However, this error I have also seen discussed in some queries. But I am unable to understand the solution.

Kindly tell me the solution.

Thank You

Regards

Sumit Kukreti

IIT JODHPUR INDIA