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Hi Everyone,
I did a band structure calculation using HSE06, the system is a orthorhombic polymer crystal. At k-point (0.0,0.5,0.0) and (0.0,0.0,0.0), the highest occupied band is at band number 34 and the lowest unoccupied band is at band number 35, but for the other k-points, the highest occupied band and the lowest unoccupied band are at band number 36 and 37,respectively.
k-point 17 : 0.0000 0.5000 0.0000
.........
33 -4.5848 2.00000
34 -4.5543 2.00000
35 -2.4563 0.00000
36 -2.4323 0.00000
37 -2.1657 0.00000
..........
k-point 18 : 0.0000 0.0000 0.0000
.............
33 -4.6320 2.00000
34 -4.5209 2.00000
35 -2.5403 0.00000
36 -2.4575 0.00000
37 -2.1656 0.00000
............
k-point 19 : 0.0000 0.0000 0.5000
..............
33 -4.2578 2.00000
34 -4.2510 2.00000
35 -4.1068 2.00000
36 -4.0843 2.00000
37 1.8118 0.00000
.............

Then I increased the number of k-points and did the band structure calculation again. The results are as follow:
k-point 33 : 0.0000 0.5000 0.0000
..........
33 -4.5828 2.00000
34 -4.5561 2.00000
35 -2.4833 0.04174
36 -2.4598 0.00691
37 -2.1523 0.00000
...........
k-point 34 : 0.0000 0.0000 0.0000
..............
33 -4.6340 2.00000
34 -4.5210 2.00000
35 -2.5680 1.28198
36 -2.4859 0.04986
37 -2.1518 0.00000
..............
k-point 35 : 0.0000 0.0000 0.5000
.............
33 -4.2537 2.00000
34 -4.2462 2.00000
35 -4.1042 2.00000
36 -4.0829 2.00000
37 1.8281 0.00000
............

Can someone please tell me what is going on here, and how to fix this problem? Thank you very much!

Please give us more information:
1. How many electrons in the system.
2. Is it insulating or metallic.
Best,

The system is a polymer with Ge on the backbone,it has 72 valence electrons and PBE predicts that it is a conducting polymer with band gap close to 0.