![]() One can learn whether the crystal reached equilibrium or was shaped kinetically, learn about the edge-structures, and the environment. One century later, the advent of two-dimensional (2D) materials 6, 7, 8, 9 made such analysis particularly appealing, helped by a daily growing abundance of shape imagery (it is easier to characterize a 2D rather than a three-dimensional (3D) shape, not to mention improved microscopy). If the exterior energy density, such as the angle-dependent surface energy ε( a), is given for all direction angles a, this should be sufficient to define the crystal shape, as epitomized by the famed Wulff construction 2, 3, 4, 5-a geometrical recipe derived from surface energy, in which the answer emerges as an envelope of planes or lines that are distanced by ε( a) from some point and drawn for all directions a. For us to predict a crystal shape, such an approach is impossible, and so theories usually reduce the search to the exterior (surface or edge) energy minimization only 1, 2, whereas the interior-bulk (volume or area) remains invariant. Crystals-oblivious to this fundamental principle-achieve their shapes by billions of constituent atoms relentlessly performing a trial and error experiment until they reach the equilibrium shape. Physical systems in equilibrium arrive at a state of minimal energy. We instantly associate the very word crystal with a shape (and perhaps color, or the lack of it), which has often been perfected through slow geological formation or craftsmanship. We demonstrate it for challenging materials such as SnSe, which is of C 2v symmetry, and even AgNO 2 of C 1, which has no symmetry at all. Here we show how one can proceed with auxiliary edge energies towards a constructive prediction, through well-planned computations, of a unique crystal shape. If the crystal surface/edge energy is known for different directions, its shape can be obtained by the geometric Wulff construction, a tenet of crystal physics however, if symmetry is lacking, the crystal edge energy cannot be defined or calculated and thus its shape becomes elusive, presenting an insurmountable problem for theory. It is also a visible macro-manifestation of the underlying atomic-scale forces and chemical makeup, most conspicuous in two-dimensional (2D) materials of keen current interest. Theoretical calculations confirm the rationality of the experimental scheme and elucidate the underlying reason for the fungistatic and fungicidal activity against Candida albicans.The equilibrium shape of crystals is a fundamental property of both aesthetic appeal and practical importance: the shape and its facets control the catalytic, light-emitting, sensing, magnetic and plasmonic behaviors. A correlation between the exposed surfaces and antifungal activity was revealed, and an explanation to this behavior that arises from different morphologies and structural data was provided. A large decrease in surface energy for the (111) surface provided the experimental morphology for crystals synthesized using water and ethanol as solvents when the surface energies for both (011) and (001) surfaces increased, the crystal morphology obtained using ammonia as a solvent was reproduced. The experimental morphology was obtained by varying the surface energy ratio for each facet. The (011) orientation was the predominant surface in the morphology. The thermodynamic equilibrium shape of the β-Ag2MoO4 crystals was determined based on the surface energies calculated using Wulff construction. The optical properties were investigated by UV-Vis spectroscopy and photoluminescence measurements at room temperature. The samples were characterized by X-ray diffraction, micro-Raman spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy with energy dispersive spectroscopy. β-Ag2MoO4 samples were prepared by a co-precipitation method using different solvents (water, ethanol and ammonia), and their antifungal activity against Candida albicans was investigated. In this study, we investigate the structure, antifungal activity, and optical properties of β-Ag2MoO4 using experimental and theoretical approaches.
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