An in-depth understanding of the water and mineral interaction is indispensable for many fields including enhanced oil recovery, global carbon cycle, and environment sustainability. In this work, using first-principles calculations based on density functional theory supplemented with semiempirical DFT-D2 dispersion corrections, we study the structural, energetic, electronic, and optical properties of hydrated calcite (104) surfaces via an exhaustive sampling of all the adsorption sites with up to full (monolayer) water coverage. Our results suggest that on-top Ca surface sites are the most energetically favorable sites for water adsorption. Also, we found sizable differences in the binding energies among the configurations having the same number of adsorbed water molecules, highly likely due to the differences in the organization and tilting of Ca_s-O_s octahedra along with the differences in the Ca_s-O_w bond distance and Ca_s-O_w-H bond angles. We also report intriguing variations in the optical absorption spectra of hydrated calcite (104) surfaces with respect to pristine (anhydrous) calcite (104) surface. Interestingly, we find significant variations in the optical absorption spectra among the hydrated calcite (104) surfaces having the same of adsorbed water molecules. The findings in this theoretical study would help in improving our fundamental understanding of hydrated calcite (104) surface that has impact on many processes in nature.

深入了解水和矿物的相互作用对于许多领域都是必不可少的，包括提高石油采收率、全球碳循环和环境可持续性。在这项工作中，我们使用基于密度泛函理论的第一性原理计算并辅以半经验 DFT-D2 色散校正，通过对所有吸附的详尽采样来研究水合方解石 (104) 表面的结构、能量、电子和光学性质。具有高达全（单层）水覆盖的站点。我们的结果表明，顶部 Ca 表面位点是最有利于水吸附的位点。此外，我们发现具有相同吸附水分子数的构型之间的结合能存在相当大的差异，这很可能是由于 Ca 的组织和倾斜的差异_s -O _s八面体以及 Ca _s -O _w键距和 Ca _s -O _w -H 键角的差异。我们还报告了水合方解石 (104) 表面相对于原始（无水）方解石 (104) 表面的光学吸收光谱的有趣变化。有趣的是，我们发现具有相同吸附水分子的水合方解石 (104) 表面之间的光学吸收光谱存在显着差异。这项理论研究的发现将有助于提高我们对水合方解石 (104) 表面的基本理解，该表面对自然界中的许多过程产生影响。