April 2018: The ".mod" and ".krz" model column mass, "RHOX", scale (that is not used in MARCS or in its spectrum synthesis relatives BSYN or Turbospectrum) were recalculated by taking the sphericity effects into account for spherical models and actually summing up (integrating) the mass above one cm² at each depth. Previously RHOX ws simply calculated as the total pressure divided by the models' nominal log g. For consistency the plane-parallel models were also recalculated accordingly.

April 2018: 5 models were also replaced, listed here.

April 2012: The ".mod" models were pruned from some unphysical data and one digit added to values of pressures and density. The "readmarcs.f" programme was adjusted accordingly.

July 2011: The ".krz" model number densities (table column 4) were corrected by subtraction of the electron number densities from the total particle number densities. This has a negligibly small effect below 5500 K.

February 2011: A small subgrid of 280 spherical red supergiant (RSG) models was added. Their masses are 15 M_Sun, the effective temperatures range from 3300 to 4500 K, the logarithmic surface gravities from −0.5 to +1.0, the microturbulence parameter is 5 km/s, and the overall metallicities range from −1.0 to +0.5. The relative elemental abundances are all solar which places the metal-poor RSG models in the "alpha-poor" metallicity class and those with solar and higher overall metallicity in the "standard" class.