We screened a hypothetical MOF database referred to as the USMOF DB initially constructed in Ref. . The building blocks of MOFs used in this prior study were extracted from the CoRE MOF 2019 DB and recombined in new combinations on a large number of topologies to create a database of novel MOFs using PORMAKE . In this work, we employ the subset of 9,524 hypothetical "ultrastable" MOFs, which were predicted to possess high thermal stability and stability upon activation. Ultrastability is defined as a thermal decomposition temperature (Td) greater than one standard deviation (87℃) above the mean Td (359℃) in the experimental data set (i.e., Td of 446℃ or higher), along with a ML-predicted 30 probability of the structure being stable exceeding 50%. As in prior work, we define edges (i.e., organic building blocks with two connection points) and nodes (i.e., any organic or inorganic component with more than two connection points) instead of linkers and SBUs to provide a clear breakdown of a MOF structure into mutually exclusive building blocks. The 9,524 "ultrastable" subset of USMOF DB consists of MOFs with different configurations of inorganic nodes, organic nodes, and organic edges: (1) one inorganic node and one edge (1inor-1edge, 5,213 MOFs), (2) one inorganic node, one organic node, and one edge (1inor-1org-1edge, 2,918 MOFs), and (3) two inorganic nodes and one edge (2inor-1edge, 1,393 MOFs). Calculations of mechanical properties, which were carried out with the LAMMPS package (ver. 29Sep2021) in prior work , were further used to narrow down the set of structures examined in this work. For the 9,524 ultrastable MOFs, the Voigt-Reuss-Hill bulk modulus (KVRH), a measure of mechanical stability, was previously successfully obtained for 7,330 materials. In the present work, we define "ultrastable" mechanical behavior as a MOF with KVRH exceeding 5 GPa. The mechanically stable subset includes 1,102 MOFs, categorized by their connectivity and composition as follows: (1) one inorganic node and one edge (722 MOFs, 65.5%),