Dear VASP users,

Warm Greetings of the Day !!!!

I am calculating the PIEZOELECTRIC TENSOR for Monolayer MoS2 nanosheet. I got the two set  of values which appended as below (1). Ionic contribution to field (2). To the field only,

Question-- My values for the PIEZOELECTRIC TENSOR for Monolayer MoS2 is not in-line with the reported literature values for the same. The reported experimental value is e11(MoS2 mono-layer) = 0.51 C/m^2 and the same with layer thickness normalized is e11= 2.9 × 10–10 C m−1. I am getting the value as 0.14542 C/m^2. How I can achieve this value. Any comment on the below appended results and unit conversion from C/m^2 to C/m, I will highly well appreciate any help from you.

* I have fully optimized structure with well optimized parameters and Band gap is in good agreement.

1. PIEZOELECTRIC TENSOR IONIC CONTR for field in x, y, z (C/m^2)

XX YY ZZ XY YZ ZX

--------------------------------------------------------------------------------

x -0.00001 -0.00002 -0.00005  0.02215 -0.00000  0.00000

y  0.02211 -0.02214 -0.00004 -0.00000  0.00000 -0.00000

z  0.00000  0.00000  0.00000 -0.00000  0.00000  0.00000

2.

PIEZOELECTRIC TENSOR for field in x, y, z (e Angst)

XX YY ZZ XY YZ ZX

--------------------------------------------------------------------------------

x 0.00119 -0.00078 0.00018 1.74959 0.00000 0.00000

y 1.74473 -1.74913 -0.00009 0.00000 0.00000 0.00000

z 0.00000 0.00000 0.00001 0.00000 -0.00000 0.00000

PIEZOELECTRIC TENSOR for field in x, y, z (C/m^2)

XX YY ZZ XY YZ ZX

--------------------------------------------------------------------------------

x -0.00000 0.00000 0.00000 0.14542 0.00000 0.00000

y 0.14542 -0.14542 0.00000 0.00000 0.00000 0.00000

z 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000