water-rock interaction &
geochemical modeling Simplified
A New Approach to Geochemical Modeling
Geochemical speciation models calculate the equilibrium distribution of dissolved species in water -- which ions, complexes, and minerals are present, and in what concentrations. Kinetic reaction models add how this water reacts with minerals over time. Most programs in use today share a common mathematical foundation developed decades ago. Sym8 takes a fundamentally different approach, solving the full chemical system as a single unified problem rather than decomposing it into parts.
What is Sym8?
Sym8 is a geochemical modeling package for chemical equilibria in aqueous systems. It currently consists of two components: Sym8.EQ, which solves equilibrium speciation, and Sym8.BK, which models batch-type kinetic reactions. Both components share the same underlying mathematical framework.
The goal of Sym8 is the same as that of any water–rock interaction program: given a water composition and a set of thermodynamic data, compute the concentrations of dissolved species present in the system. The kinetic component extends this capability by describing how minerals dissolve and precipitate through time, and how these reactions modify water chemistry and properties.
What distinguishes Sym8 from traditional programs is how these calculations are carried out. Sym8.BK is designed to provide a more transparent and physically consistent view of how mineral reactions control water chemistry through time.
Why Sym8?
Conceptual clarity
Chemistry and mathematical structure are represented directly, making model assumptions easier to understand and interpret.
Realistic simulation scenarios
Mineral reactions, evaporation, gas exchange, and mass-transfer processes are simulated as an integrated single chemical system responding to variable environmental conditions.
Intuitive interface design
The modeling workflow and the structure of the software reflects the fundamental scientific formalism.
Predictable numerical behavior
A clearly defined single solution framework produces consistent results across strongly coupled reaction systems.
Focus on the scientific problem
Users spend time defining reaction systems rather than managing layers of modeling conventions.
How Sym8 Works
No basis chemical species
Solute composition is defined directly from chemical elements rather than from a selected set of basis species.
Single chemical system framework
Chemical reactions, solute concentrations, and elemental mass-balance conditions are solved together within a single mathematical system, without separating basis and secondary species.
Integrated kinetic reactions (Sym8.BK)
Kinetic reaction contributions modify elemental mass-balance equations directly within the unified system, avoiding secondary correction steps and operator-splitting methods.
Integrated gas, adsorption, and microbial processes
Gas–water equilibrium (Sym8.EQ), air–water gas exchange (Sym8.BK), adsorption and surface complexation, and microbial reactions are all handled within the same chemical system framework.
Strict elemental mass conservation
Evaporation, inflow, and outflow of water (Sym8.BK) are treated as elemental mass-balance conditions at each timestep rather than as external adjustments to the chemical system framework.
Petrophysical response to water chemistry (Sym8.BK)
Mineralogical composition and reactive surface areas evolve dynamically as water composition changes.
Relational thermodynamic database
Chemical species, reactions, thermodynamic data, and related chemical and physical properties are organized within a relational database rather than distributed text files, allowing centralized management and access.