Inconsistency in VASP Calculations for the Same Element from API

Materials Project
7

/home/0/.local/lib/python3.11/site-packages/pymatgen/core/structure.py:3087: EncodingWarning: We strongly encourage explicit encoding, and we would use UTF-8 by default as per PEP 686
with zopen(filename, mode=“rt”, errors=“replace”) as file:
/home/0/.local/lib/python3.11/site-packages/pymatgen/core/structure.py:3087: EncodingWarning: We strongly encourage explicit encoding, and we would use UTF-8 by default as per PEP 686
with zopen(filename, mode=“rt”, errors=“replace”) as file:

기존 당신이 저에게 주신 코드는 encoding 에러가 발생했습니다.
이에 저는 아래와 같이 코드를 수정하였습니다.

import warnings

warnings.filterwarnings("ignore", message=r".*explicit `encoding`.*")

from pymatgen.analysis.structure_matcher import StructureMatcher
from pymatgen.core import Structure

matcher = StructureMatcher()
s_bp = Structure.from_file("POSCAR_bp")
s_bcp = Structure.from_file("POSCAR_bcp")

for s in (s_bp, s_bcp):
    for k in s.site_properties:
        s.remove_site_property(k)

print(matcher.fit(s_bp, s_bcp))

위 코드를 실행해서 제가 얻은 값은 True 입니다.

POSCAR_bp

Co1 F3
1.0
2.6472384033333332 1.5283830066666670 2.1613651899999997
0.0000023733333334 -3.0567679833333337 2.1613661900000003
2.6472397666666665 -1.5283839666666665 -2.1613641800000001
Co F
1 3
direct
0.9999965233333332 0.9999965233333331 0.0000034766666666 Co3+
0.5000006766666666 0.0001207133333332 0.0001185800000000 F-
0.0001207133333334 0.9998814199999999 0.4999993233333332 F-
0.9998810866666666 0.5000006766666668 0.9998789533333333 F-

POSCAR_bcp

Co1 F3
1.0
-2.6472393272282879 -1.5283843381846158 2.1613651866667190
-2.6472393272282879 1.5283843381846154 -2.1613651866667194
0.0000000000000000 -3.0567686763692312 -2.1613651866667190
Co F
1 3
direct
0.9999999999999999 0.0000000000000001 0.0000000000000001 Co3+
0.0001198116666665 0.5000000000000001 0.0001198116666667 F-
0.9998801883333335 0.9998801883333335 0.4999999999999999 F-
0.5000000000000000 0.0001198116666666 0.9998801883333335 F-

더 나아가 band gap을 아래의 코드를 활용해 계산하였습니다.
I referenced your other answer.

from pymatgen.io.vasp import Vasprun

vasprun = Vasprun("bcp_vasprun.xml") # or the path to your vasprun.xml
gap = vasprun.get_band_structure(efermi="smart").get_band_gap()
print("band gap from vasprun:", gap)

For B > C > P structure
band gap from vasprun: {‘direct’: False, ‘transition’: ‘(0.500,0.500,0.500)-(0.000,0.000,0.000)’, ‘energy’: 0.20450000000000002}

For B > P structure
band gap from vasprun: {‘energy’: 0.0, ‘direct’: False, ‘transition’: None}

Now, regarding the question you asked,

  1. Since the material I’m examining is a metal, using the default value LEGACY might be inaccurate. (Though I don’t fully understand, is it correct that the default sets the Fermi level below VBM and CBM like insulators?)

So I modified it to EFERMI = MIDGAP and ran the codes again, but
the error keeps occurring as shown in the image.

  1. The initial structures are identical in both cases.

  2. The Band Gap is as shown above.
    According to those results, does this mean that Co1F3, which should be a metal, is behaving like a semiconductor (with a band gap of ~0.2045 eV) in the b>c>p structure?

How can it be divided into conductor/semiconductor when the structures are identical and the Total energy (though it has no physical meaning) is the same?

I tried to keep it as short as possible, but it ended up being long again.
I apologize.