WebMO Molecule Editor vs NMR Calculator 2

WebMO allows users to build and view molecules in 3-D, visualize orbitals and symmetry elements, lookup chemical information and properties from external databases, and access state-of-the-art computational chemistry programs. WebMO is recommended for students and faculty in high school, college, and graduate school who desire mobile access to molecular structures, information, and calculations. WebMO capabilities include: - Build molecules by drawing atoms and bonds in a 3-D molecular editor, or by speaking the name (e.g., “aspirin”) - Optimize structures using VSEPR theory or molecular mechanics - View Huckel molecular orbitals, electron density, and electrostatic potential - View molecular vibrations - View point group and symmetry elements of molecules - Lookup basic molecular information, including IUPAC and common names, stoichiometry, molar mass - Lookup chemical data from PubChem and ChemSpider - Lookup experimental and predicted molecular properties from external databases (NIST, Sigma-Aldrich) - Lookup IR, UV-VIS, NMR, and mass spectra from external databases (NIST, SDBS) - Capture high-resolution molecular images - Save and recall molecular structures locally - Export and import structures via email WebMO is also a front-end to WebMO servers (version 14 and higher): - Supports Gaussian, GAMESS, Molpro, MOPAC, NWChem, ORCA, PQS, PSI, Quantum Espresso, VASP, Q-Chem, and Tinker computational chemistry programs - Submit, monitor, and view calculations - View formatted tabular data extracted from output files, as well as raw output - Visualize geometry, partial charges, dipole moment, normal vibrational modes, molecular orbitals, and NMR/IR/UV-VIS spectra

The app shows a list of isotopes with non-zero nuclear spin angular momentum. Select an isotope to view its NMR properties and calculate fundamental NMR parameters. Information section For a chosen isotope, this section displays the atomic symbol with mass number, nuclear spin angular momentum, gyromagnetic ratio, and natural abundance. Calculator section Update any one parameter in a subsection to recalculate the others. - Larmor frequencies: External magnetic field and the corresponding Larmor frequencies for the chosen isotope, the proton, and the free electron. - Time domain: Number of data points, acquisition duration, and dwell time. - Frequency domain: Number of data points, spectral width, and frequency resolution. - Pulse 1: Pulse duration, flip angle, and RF amplitude in Hz and μT. - Pulse 2: Pulse duration, flip angle, RF amplitude in Hz, and RF power relative to Pulse 1. - Ernst angle: Ernst angle and repetition time for a given T₁ relaxation time. NMR Assistant An on-device AI assistant scoped to NMR topics, available where Apple Intelligence is supported. Ask questions in plain language — the assistant answers using the same calculation engine that powers the calculator, so results are always physically consistent.