Questions tagged [databases]

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22 views

Do any decent thermochemical databases exist? [duplicate]

The more thermochemical properties the better, but specific heat/ specific heat capacity is what I am looking for.
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1answer
44 views

What is the meaning of the phase state label (cr,l) appearing in ATcT thermochemical data tables?

I was examining data associated with this post on the heat of solution of ammonium nitrate when I came upon the NIST ATcT data page which lists the heat of formation of $\ce{(NH4)NO3(cr,l)}$. In this ...
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50 views

What does “reaction rank” in Reaxys stand for?

By exporting some search results from Reaxys, I found "Reaction rank" to be one of the columns in the Excel file. In my file, values descend from 107 to 52 and skip some values in-between too. Does ...
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1answer
32 views

Is there any book where specific heat capacities are given?

I want to find the value of the specific heat capacity of aluminium nitrate nonahydrate, in order to calculate mixing effects in a chemical reaction. I am looking for a source, such as a book or link ...
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2answers
325 views

How can I get xyz coordinates of atoms of a unit cell structure from CIF format files?

I'm trying to run DFT or other 1st principle simulation of Pyrope ($\ce{Mg3Al2Si3O12)}$ and Grossular $\ce{(Ca3Al2[SiO4]3)}$ unit cell structure. So, I'm looking for unit cell xyz periodic box ...
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395 views

What is a good source for large tables on the properties of water?

I'm currently doing an investigation for school on finding the Clausius-Clapeyron relation/gradient for boiling water and comparing it to the gradients along my line of best fit. It is given by the ...
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55 views

Looking for experimental data for titration curves

I am looking for real, open source and free experimental dataset (not image, scan of table) of acid/base titration curves: pH versus titrant volume for many combination (strong/weak acid/base, ...
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1answer
119 views

Where can I find reliable data for melting points of organic compounds?

I'm interested in the melting/freezing points of organic compounds, but the online literature has data that's all over the map. I can understand that especially for isomers of alkanes, pure samples ...
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67 views

What is the difference between ΔfH and H-H° in NIST–JANAF tables?

Can someone explain the difference between $Δ_\mathrm{f}H$ and $H-H^\circ$ in NIST–JANAF tables?
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31 views

Online list of water of crystallisation?

I was extremely happy to recently receive a copy of the Nuffield Revised Book of Data but was somewhat disappointed to find that it did not list data on the water of crystallisation for various ...
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109 views

Spectral database in the UV-Vis/NIR and IR regime

I'm searching for a bunch of spectra (some tens), preferably with intense bands in the Vis spectrum, to play around with (calculating chromaticity, etc.). They should range from 250 nm to 2500 nm (UV-...
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155 views

Pseudo 3D skeletal structure style which emphasizes geometry

If one searches and navigates to a wiki page for, say, dichlorodifluoromethane one sees the 2D skeletal structure of the compound as below This representation appears to be of a particular style that ...
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1answer
100 views

Where can I find example MS, IR, NMR spectra for teaching molecular spectroscopy?

I am teaching a course on analytical chemistry, and I would like to give my students MS, IR and NMR spectra to practice with. It would be ideal if they could analyze spectra in a more "realistic" way ...
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1answer
85 views

Help on alternative terpene names and naming schemes

I am a software developer and currently parsing data involving terpene profiles of plant samples. The data in question uses different ways of naming the same terpenes in-between samples and since this ...
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86 views

Experimental bond lengths and binding energies of diatomic molecules

Is it possible to find the experimental values of the bond length and the binding energy of the diatomic molecules $\text H_2$, $\text{Be}_2$, and $\text{Ar}_2$ in one source? I found a lot of ...
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89 views

How to find chemical market value [closed]

I would like to retrieve pricing information for specific chemicals. Is there a centralized resource for this? Edit: I want to clarify that this type of data is to conduct a techno-economic study. I ...
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1answer
308 views

Molar absorption coefficient of H2SO4(aq) for UV-vis spectrophotometry

I am wondering if there is anything in the literature that can tell me what is the molar absorptivity (i.e. molar extinction coefficient) of aqueous sulfuric acid at a given wavelength (in my case, I ...
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2answers
538 views

What is the correct regular expression for InChI?

When I look for a regular expression for InChI, I succeed on EBI's MIRIAM Registery website: ...
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77 views

Which organic compounds have the most strongly negative enthalpies of formation?

I've been using the NIST Webbook to list organic compounds and look at their heats of formation (kJ/g, not mol). If I limit myself to three carbons, I still get over 400 results. I can use some ...
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61 views

Where can I find ranges of isotope abundances?

I'd like to know how much stable isotopes like $\ce{^{13}C}$, $\ce{^2H}$, $\ce{^{17}O}$ and $\ce{^{18}O}$ deviate from their natural abundances in the earth's crust among all possible compounds we may ...
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Where can I find a downloadable database of basic physical and chemical properties?

The web has many online databases of properties of compounds locked behind search interfaces, but I can't find anything you can actually download. I want a corpus of data that might allow me to, say, ...
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3answers
211 views

What is the best way to convert SMILES strings to file names?

I would like to convert SMILES strings into file names. There are many characters to avoid in file names, i.e. \/:*?"<>| or maybe even ...
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25 views

Deliquescence database

I am looking for a database or printed document providing the RH0 (relative humidity above which deliquescence will occur) for inorganic salts. I've looked everywhere on the internet can find nothing.
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1answer
2k views

Free chemical reactions database

I'm creating a program, which predicts reactions of compound. So, I need a database of chemical reactions. And I need both inorganic and organic reactions. But I can't use Scifinder or Reaxys because ...
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1answer
138 views

Algorithm used by PubChem to determine the 2D layout assignment for Compound entries?

The PubChem database provides 2D structures for entries in its Compounds database: ftp://ftp.ncbi.nlm.nih.gov/pubchem/Compound/ (ftp link to download examples) On the page linked below, under the "...
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436 views

Calculating Surface Area of Compound

Is there any way to calculate the surface area of compounds such as 2,5-dimethylhexane or 3-methylpentane? If not, is there a database that has information on surface area of these compounds (not ...
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1answer
152 views

Need help interpreting this data table (provided below)

I am confused about this data table. Can someone please explain how this person got a linear alkanes of differing molar masses? (I know some basics of organic chemistry, but I'm still learning.) Are ...
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216 views

Chemical time scales

In calculating UV/VIS spectra with computational procedures (say, TD-DFT), it is commonly assumed that the geometry of the ground-state is still valid also for the excited state due to the short time ...
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122 views

Validation of _atom_site_frac_*: Range outside of [0,1)?

I have the following cif file ...
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1answer
239 views

where can I find experimental compressibility factor values?

I am interested in experimental compressibility factors for various gases, such as methane and carbon monoxide. Not only for standard pressures and room temperature, but in a range from 1 to a few ...
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1answer
977 views

Finding cubic ice CIF files in crystal database

Could anyone please tell me where I could find the the structure of cubic ice (ice Ic) as a CIF file? I have been searching the cambridge structural database using "H2O", "water", "dihyrogen oxide" ...
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1k views

Is there an open Chemical database that includes GHS/CLP classifications?

I'm looking for a Chemical database that is up to date (via a firm, experts or crowdsourcing) is open and free to use (best via an API) contains the CLP/GHS classifications for chemicals I have not ...