# this file is part of refractiveindex.info database
# refractiveindex.info database is in the public domain
# copyright and related rights waived via CC0 1.0

REFERENCES: |
    M. Tharrault, S. Ayari, M. Arfaoui, E. Desgué, R. Le Goff, P. Morfin, J. Palomo, M. Rosticher, S. Jaziri, B, Plaçais,P. Legagneux, F. Carosella, C. Voisin, R. Ferreira, E. Baudin.
    Optical absorption in indirect semiconductor to semimetal PtSe<sub>2</sub> arises from direct transitions.
    <a href="https://doi.org/10.1103/PhysRevLett.134.066901"><i>Phys. Rev. Lett.</i> <b>134</b>, 066901 (2025)</a>
    (Numerical data kindly provided by Marin Tharrault)
COMMENTS: |
    3L CVT-grown exfoliated crystal.
    The optical indexes are computed from the 2D surface conductivity using σ<sub>2D</sub>·Z<sub>0</sub> = −2π<b>i</b>·(t/λ)·(ε<sub>r</sub>−1), where Z<sub>0</sub> is the impedance of free space, <b>i</b> the imaginary unit, t the equivalent layered stack thickness and λ the free space wavelength. We use t = N<sub>L</sub> t<sub>0</sub> with t<sub>0</sub> = 5.1 Å the single layer thickness.
    The measurement method accuratly determines Im{ε<sub>r</sub>} = 2nk, but only Re{ε<sub>r</sub>} = n<sup>2</sup> - k<sup>2</sup> as long as the optical absorption is non-zero.
DATA:
  - type: tabulated nk
    data: |
        0.41536 4.58532 1.96277
        0.41816 4.52479 2.00773
        0.42100 4.52653 2.02785
        0.42388 4.50592 2.05252
        0.42680 4.44679 2.11460
        0.42975 4.44824 2.13208
        0.43275 4.44350 2.18573
        0.43580 4.46173 2.19921
        0.43888 4.44900 2.23343
        0.44201 4.40960 2.29396
        0.44519 4.43978 2.29003
        0.44841 4.44303 2.30648
        0.45167 4.43651 2.33359
        0.45499 4.44977 2.33892
        0.45835 4.46363 2.34516
        0.46177 4.47763 2.35042
        0.46523 4.47591 2.38086
        0.46875 4.49177 2.39039
        0.47232 4.52579 2.37747
        0.47595 4.54410 2.39097
        0.47963 4.57096 2.38822
        0.48337 4.54137 2.44467
        0.48717 4.58187 2.42662
        0.49103 4.57667 2.45977
        0.49495 4.56389 2.49990
        0.49893 4.59331 2.50275
        0.50298 4.62592 2.49113
        0.50709 4.60505 2.53663
        0.51128 4.63885 2.54007
        0.51553 4.63122 2.56830
        0.51985 4.65510 2.57191
        0.52425 4.65012 2.59995
        0.52872 4.63072 2.64262
        0.53327 4.68374 2.60142
        0.53789 4.66325 2.62892
        0.54260 4.66880 2.64455
        0.54739 4.70438 2.61323
        0.55227 4.67349 2.66254
        0.55723 4.69545 2.66588
        0.56229 4.69043 2.69232
        0.56743 4.71365 2.69732
        0.57268 4.74841 2.71109
        0.57801 4.73280 2.75428
        0.58346 4.79058 2.75554
        0.58900 4.79273 2.79965
        0.59465 4.79731 2.86958
        0.60041 4.75725 2.98610
        0.60628 4.68987 3.15478
        0.61227 4.73385 3.20073
        0.61838 4.78952 3.23471
        0.62461 4.88073 3.22954
        0.63096 4.92916 3.26498
        0.63745 5.01494 3.25271
        0.64407 5.10284 3.22333
        0.65084 5.11434 3.26771
        0.65774 5.19525 3.22593
        0.66479 5.07830 3.34174
        0.67200 5.16585 3.27741
        0.67937 5.18938 3.26358
        0.68689 5.25604 3.22798
        0.69459 5.29802 3.21237
        0.70246 5.39267 3.15314
        0.71051 5.45641 3.12764
        0.71875 5.54901 3.07674
        0.72718 5.62797 3.04094
        0.73581 5.72177 2.97575
        0.74465 5.79781 2.91990
        0.75370 5.86626 2.86211
        0.76298 5.91658 2.79690
        0.77249 5.96498 2.72391
        0.78223 6.01556 2.63161
        0.79223 6.04704 2.52803
        0.80249 6.04808 2.44437
        0.81301 6.03581 2.37498
        0.82382 6.04959 2.28136
        0.83491 6.06670 2.16742
        0.84631 6.07819 2.05163
        0.85802 6.11898 1.90134
        0.87006 6.07865 1.82765
        0.88245 6.06990 1.73158
        0.89519 6.02956 1.65328
        0.90831 5.99854 1.57671
        0.92182 5.97344 1.49932
        0.93573 5.93803 1.45071
        0.95007 5.90694 1.38365
        0.96486 5.91776 1.30934
        0.98011 6.15049 1.06587
        0.99586 6.15528 1.02746
        1.01212 6.17820 0.97049
        1.02891 6.18924 0.93382
        1.08283 6.15653 0.76358
        1.10208 6.17026 0.71978
        1.12203 6.15176 0.66661
        1.14271 6.18056 0.60429
        1.16417 6.16871 0.51434
        1.18645 6.13611 0.46844
        1.20960 6.10118 0.41772
        1.23367 6.04211 0.38751
        1.25860 5.97640 0.35281
        1.28468 5.93319 0.32817
        1.31186 5.87875 0.30467
        1.34022 5.82628 0.30329
        1.36984 5.84747 0.28670
        1.40079 5.72028 0.27600
        1.43318 5.63368 0.29850
        1.46709 5.65001 0.28402
        1.50266 5.70571 0.24026
        1.53999 5.68513 0.22021