Analytical fits of photoionisation (bound-free) cross-sections from exited levels of ions with more than two electrons. The fits are based on the numerical tables computed by the Opacity Project (OP) and presented in the TOPBase database. The cross-section for each considered level was fitted using the following expression: ( \sigma(E) = \sigma_{\rm th} \left(A \bar E ^{p/2}+(1-A)\bar E^{1+p/2}\right) )where (\bar E =E_{\rm th}/E ) and  (E ) is the photon energy. Only a few energy levels were considered with the lowest excitation energies, typically not exceeding a quarter of the ionization energy. These fits were implemented in the code, that calculates hot LTE atmospheres of white dwarfs in the Super-Soft X-ray Sources, see the referenced paper for the details.The file 'bf_cross_hot.dat' contains, for each ion, the name of ion, the level's energy and statistical weight and the fitting parameters  (E_{\rm th}, \sigma_{\rm th}, A, p ). The file 'bf_cross_hot.py' contains simple Python3 function for calculation the fitting cross-section for given ion and frequency or frequency array. In the latter case it also make a plot, if 'matplotlib' package is installed. The following ions were considered:CII, CIII, CIV, NII, NIII, NIV, NV, OII, OIII, OIV, OV, OVI, NeIII, NeIV, NeV, NeVI, NeVII, NeVIII, NaIV, NaV, NaVI, NaVII, NaVIII, NaIX, MgVI, MgVII, MgVIII, MgIX, MgX, AlVI, AlVII, AlVIII, AlIX, AlX, AlXI, SiVII, SiVIII, SiIX, SiX, SiXI, SiXII, SIX, SX, SXI, SXII, SXIII, SXIV, ArV, ArVI, ArVII, ArVIII, ArXI, ArXII, ArXIII, ArXIV, ArXV, ArXVI, CaV, CaVI, CaVII, CaIX, CaXIII, CaXIV, CaXV, CaXVI, CaXVII, CaXVIII, FeVI, FeVII, FeXI, FeXII, FeXIII, FeXIV, FeXV, FeXVI, FeXVIII, FeXIX, FeXX, FeXXI, FeXXII, FeXXIII, FeXXIV, FeXXV.

Analytical fits of photoionisation (bound-free) cross-sections from exited levels of ions with more than two electrons. The fits are based on the numerical tables computed by the Opacity Project (OP) and presented in the TOPBase database. The cross-section for each considered level was fitted using the following expression: ( \sigma(E) = \sigma_{\rm th} \left(A \bar E ^{p/2}+(1-A)\bar E^{1+p/2}\right) )where (\bar E =E_{\rm th}/E ) and  (E ) is the photon energy. Only a few energy levels were considered with the lowest excitation energies, typically not exceeding a quarter of the ionization energy. These fits were implemented in the code, that calculates hot LTE atmospheres of white dwarfs in the Super-Soft X-ray Sources, see the referenced paper for the details.The file 'bf_cross_hot.dat' contains, for each ion, the name of ion, the level's energy and statistical weight and the fitting parameters  (E_{\rm th}, \sigma_{\rm th}, A, p ). The file 'bf_cross_hot.py' contains simple Python3 function for calculation the fitting cross-section for given ion and frequency or frequency array. In the latter case it also make a plot, if 'matplotlib' package is installed. The following ions were considered:CII, CIII, CIV, NII, NIII, NIV, NV, OII, OIII, OIV, OV, OVI, NeIII, NeIV, NeV, NeVI, NeVII, NeVIII, NaIV, NaV, NaVI, NaVII, NaVIII, NaIX, MgVI, MgVII, MgVIII, MgIX, MgX, AlVI, AlVII, AlVIII, AlIX, AlX, AlXI, SiVII, SiVIII, SiIX, SiX, SiXI, SiXII, SIX, SX, SXI, SXII, SXIII, SXIV, ArV, ArVI, ArVII, ArVIII, ArXI, ArXII, ArXIII, ArXIV, ArXV, ArXVI, CaV, CaVI, CaVII, CaIX, CaXIII, CaXIV, CaXV, CaXVI, CaXVII, CaXVIII, FeVI, FeVII, FeXI, FeXII, FeXIII, FeXIV, FeXV, FeXVI, FeXVIII, FeXIX, FeXX, FeXXI, FeXXII, FeXXIII, FeXXIV, FeXXV.

The pre-calculated turning points for surface density (\Sigma), effective temperature (T_{\rm eff}) and accretion rate (\dot{M}) of S-shaped stability curve for stationary Shakura-Sunyaev viscous accretion disc. Calculations performed for 20 linearly scaled values of central source mass from (1, M_{\odot}) to (20, M_{\odot}), 20 logarithmically scaled values of viscous parameter (\alpha) from (3\cdot10^{-4}) to 0.7, 20 logarithmically scaled values of radius from (7\cdot10^7) cm to (5\cdot10^{11}) cm.The new open-source Python3 code is used to calculate the vertical structure of the disc with tabular opacity (solar chemical composition) and both convective and radiative energy transport taking into account. As a result, one can obtain S-shaped stability curve — a graphically depicted sequence of solutions of the vertical-structure equations, obtained at a single disc radius, in the coordinates of accretion rate or effective temperature versus the surface density. S-curve turn points allow to investigate the stability of disc with respect to temperature and surface density fluctuations. Reading of the data (Python3):import numpy as npdata = np.genfromtxt('Turn_points_array.dat', names=True)

The pre-calculated turning points for surface density (\Sigma), effective temperature (T_{\rm eff}) and accretion rate (\dot{M}) of S-shaped stability curve for stationary Shakura-Sunyaev viscous accretion disc. Calculations performed for 20 linearly scaled values of central source mass from (1, M_{\odot}) to (20, M_{\odot}), 20 logarithmically scaled values of viscous parameter (\alpha) from (3\cdot10^{-4}) to 0.7, 20 logarithmically scaled values of radius from (7\cdot10^7) cm to (5\cdot10^{11}) cm.The new open-source Python3 code is used to calculate the vertical structure of the disc with tabular opacity (solar chemical composition) and both convective and radiative energy transport taking into account. As a result, one can obtain S-shaped stability curve — a graphically depicted sequence of solutions of the vertical-structure equations, obtained at a single disc radius, in the coordinates of accretion rate or effective temperature versus the surface density. S-curve turn points allow to investigate the stability of disc with respect to temperature and surface density fluctuations. Reading of the data (Python3):import numpy as npdata = np.genfromtxt('Turn_points_array.dat', names=True)