Meeting 34, April 27th Theory: ZnSb Normal mode displacement vectors at gamma. And SrAlSiH dispersion curve attempts

ZnSb PROCEDURE

Take structure from literature and relax with a constant volume algorithm to minimize forces to less than 10-3 eV/Å on each atom.

Pressure at -3.68*10-3 GPa Calculate dispersion curve. All runs used a 4x4x4 kpoint grid Ecut = 35 Ha

Si dispersion curve

Si modes at gamma acoustic

Si modes at gamma 526 cm-1

ZnSb Displacement vectors at Gamma

35.85 cm-1

38.40 cm-1

43.54 cm-1

46.75 cm-1

50.33 cm-1

54.04 cm-1

54.37 cm-1

56.29 cm-1

57.07 cm-1

57.68 cm-1

61.22 cm-1

61.35 cm-1

SrAlSiH dispersion curves

Lee. et al

Table of attempts

attempt # relaxed xc occopt tsmear qpt-grid kpt-grid1to volume GGA 4 (cold smearing) 0.04 Ha 2x2x3 4x4x62to 0 Gpa GGA 4 (cold smearing) 0.04 Ha 2x2x3 4x4x63NO LDA 4 (cold smearing) 0.04 Ha 2x2x3 4x4x64NO LDA 7 (gaussian smearing) 0.02 Ha 2x2x3 4x4x65to volume LDA 7 (gaussian smearing) 0.02 Ha 2x2x3 4x4x66to 0 Gpa GGA 7 (gaussian smearing) 0.02 Ha 2x2x3 4x4x67to 0 Gpa GGA 7 (gaussian smearing) 0.02 Ha 4x4x6 4x4x68to volume LDA 7 (gaussian smearing) 0.02 Ha 4x4x6 4x4x69to volume LDA 1 (forced semiconductor) 0.02 Ha 2x2x3 4x4x6

10to 0 Gpa GGA 7 (gaussian smearing) 0.02 Ha 2x2x2 8x8x8

attempt 1

attempt # relaxed xc occopt tsmear qpt-grid kpt-grid1to volume GGA 4 (cold smearing) 0.04 Ha 2x2x3 4x4x6

attempt 2

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridto 0 Gpa GGA 4 (cold smearing) 0.04 Ha 2x2x3 4x4x6

attempt 3

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridNO LDA 4 (cold smearing) 0.04 Ha 2x2x3 4x4x6

attempt 4

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridNO LDA 7 (gaussian smearing) 0.02 Ha 2x2x3 4x4x6

attempt 5

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridto volume LDA 7 (gaussian smearing) 0.02 Ha 2x2x3 4x4x6

attempt 6

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridto 0 Gpa GGA 7 (gaussian smearing) 0.02 Ha 2x2x3 4x4x6

attempt 7

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridto 0 Gpa GGA 7 (gaussian smearing) 0.02 Ha 4x4x6 4x4x6

attempt 8

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridto volume LDA 7 (gaussian smearing) 0.02 Ha 4x4x6 4x4x6

attempt 9

attempt # relaxed xc occopt tsmear qpt-grid kpt-grid

Failed to Converge

to volume LDA 1 (forced semiconductor) 0.02 Ha 2x2x3 4x4x6

attempt 10

attempt # relaxed xc occopt tsmear qpt-grid kpt-gridto 0 Gpa GGA 7 (gaussian smearing) 0.02 Ha 2x2x2 8x8x8