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S-cloud - simulation or reality?

xirrus simulation matters

Let simulate » material properties!

«Often the knowledge of a "street number" is superior to total ignorance.»
Nino Zehnder, Even AG, Zurich, Switzerland

Have materials' properties calculated — physical properties of organic compounds, polymers, composites and mixtures — instead of tedious measurements, even if the material has not been manufactured yet. Obtaining materials' properties has never been simpler and safer.

Download the complete factsheet and manual as a PDF rather than reading online help ↓ download

Your requirements

  • The considered compounds are practically or theoretically known » ?

    type of compound
    • organic compounds and polymers (also biocompatible or biological), including silicone as well as most of the existing solvents.
    • pure compounds, mixtures and additives and functionalizations
    • often applied chemical elements only (ask in case of doubt)
    • the mixture contains little or no salts (ions).
    • The value of pH isn't extreme (between 5-9 in aqueous solution) or irrelevant.
    • no metallic or ceramic materials
    chemical structure
    • The chemical structure (the connectivity) of the contained components is known, for polymers the approximate degree of polymerisation is known (below 1500 kDa molecular weight).
    • The conformation may be unknown, it evolves and changes during the simulation.
    phase, state of aggregation
    • independent of known or unknown
    • The phase evolves in the simulation (solution, melt through environmental conditions).
    • Solid, liquid, gaseous, even mixed phases are possible (mix to complex fluids).
    • We start with a homogeneous, randomly generated mixture.
  • The requested material property is unknown or unconfirmed » ?

    hypothetical material, novel material or new situation The material has not been synthetized or mixed, the material is new or has been prepared in a new mixture, characterization hasn't been done yet.
    no measurements Experiments to derive the missing value are costly or timely or just impossible compared to simulation.
    no literature data No literature value has been found, or not for the desired environmental conditions.
    value doubted Although measured, existing literature data has been doubted. Simulation shall be the independent method to deliver hints about correctness.
    For all these reasons a simulation is worthwhile, but it cannot fully replace a perfect measurement!

Proceedings and Results

1st order
Start start online: www.xirrus.ch/matters
Order Please transmit your material data (molecular structures of components) and its environmental conditions (pressure and temperature).
Property Please order simultaneously the desired material properties from the following list. Further properties can only be programmed and analysed on separate request.
  • density in [kg/m3]
  • viscosity (shear viscosity) in [N·s/m2]
  • heat capacity in [kJ/mol/K]
  • thermal conductivity (isotropic) in [kJ/m/K/s]
  • diffusion coefficient in [cm2/s]
  • compressibility (isothermal) in [kJ/mol/l]
    elasticity modulus in [kN/mm2]
special cases Please contact us directly in special cases.

2nd confirmation
We confirm your molecular structures as soon as we have interpreted them, that occasionly sneeked in errors can be removed.
binding amount We confirm your order with a binding sum.

3rd payment
advance payment Please transfer the requested amount on our account or your order will be canceled.
literature value is existing If we can find the requested value in no time in the scientific literature, we will tell you the source and may be don't simulate the system. We will keep the money for the take-over of the literature research.

4th let simulate
simulation xirrus simulation matters simulates your material at defined environmental conditions (pressure, temperature, provided by you) in microscopic adequate size and time.
period of delivery Statistical mechanics, thermodynamic simulations in molecular details demand for high computational power. It can take days or weeks, until the result is generated. In best case, you receive the significant result one day after payment and confirmation of the structures.

5th get result(s)
result xirrus simulation matters analyses, i.e. calculates the desired material property under thermodynamic equilibrium conditions. The output will be, if not otherwise stated, in SI units. Included is the statement of the standard deviation from the calculated values.
accuracy The accuracy achievable in such simulations is methodically limited (for energies e.g. never better than +/- 0.5 kJ/mol, deviations in densities up to 5% have to be tolerated, and much more). You cannot expect wonders.
guarantee In case of proofable big deviation* of at least three independently published, but corresponding literature values [scientific sources] and complaint within two months after payment, after announcement and confirmation of the fact, you get your money back. Such a case will help us identify certain model limitations and to fine-tune our models to the requests.
*an error will be stated, if the deviation is bigger than one order of magnitude from the usual deviation of comparable calculations.

Why simulate material properties?

enlightning Many material properties aren't linearly coupled to their environmental conditions, which makes extrapolation rather difficult, especially if not enough indications do exist.
  • High temperatures or pressures demand for high performance equipment for experiments and measurement technology. Not every situation allows for this equipment or measuring devices.
  • A literature or patent research leads to no results but is time consuming.
→ The simulation is automated to a great extent, therefore competitive.
prospective Exactly in the planning and development phase new materials can be analysed virtually and significantly accelerate your development.
simple Just start online: www.xirrus.ch/matters

scientifically based fundamentals

molecular dynamics simulation xirrus simulation matters is based on classical Molecular Dynamics simulation. All molecules including their atoms, bonds and physical models with mobility of conformations and conservation of momentum at collisions are calculated as the thermal velocity would demand during time. Simply spoken, the atoms play billard in 3D. For productive software we use GROMOS and Gromacs.
force-field (model) The models depend on their chemical environment and the individual fragments and have been developed over decades. We apply GROMOS force-fields and our own developments thereof.
expertise Much knowledge and experience of xirrus goes into the derivation of new models and new combinations of models, as well as into the parameters and our services.