Data

To find out how to fetch data in bulk, check out the documentation about data access.

Elements

The following data are currently available:

Name

Type

Comment

Unit

Data Source

abundance_crust

float

Abundance in the Earth’s crust

mg/kg

[23]

abundance_sea

float

Abundance in the seas

mg/L

[23]

annotation

str

Annotations regarding the data

atomic_number

int

Atomic number

atomic_radius

float

Atomic radius

pm

[53]

atomic_radius_rahm

float

Atomic radius by Rahm et al.

pm

[45, 46]

atomic_volume

float

Atomic volume

cm3/mol

atomic_weight

float

Atomic weight([1])

[35, 63]

atomic_weight_uncertainty

float

Atomic weight uncertainty([1])

[35, 63]

block

str

Block in periodic table

boiling_point

float

Boiling temperature

K

[22]

c6

float

C_6 dispersion coefficient in a.u.

a.u.

[13, 56]

c6_gb

float

C_6 dispersion coefficient in a.u. (Gould & Bučko)

a.u.

[21]

cas

str

Chemical Abstracts Serice identifier

covalent_radius_bragg

float

Covalent radius by Bragg

pm

[10]

covalent_radius_cordero

float

Covalent radius by Cerdero et al.([2])

pm

[16]

covalent_radius_pyykko

float

Single bond covalent radius by Pyykko et al.

pm

[43]

covalent_radius_pyykko_double

float

Double bond covalent radius by Pyykko et al.

pm

[42]

covalent_radius_pyykko_triple

float

Triple bond covalent radius by Pyykko et al.

pm

[44]

cpk_color

str

Element color in CPK convention

HEX

[61]

critical_pressure

float

Critical pressure

MPa

[22]

critical_temperature

float

Critical temperature

K

[22]

density

float

Density at 295K([9])

g/cm3

[23, 66]

description

str

Short description of the element

dipole_polarizability

float

Dipole polarizability

a.u.

[51]

dipole_polarizability_unc

float

Dipole polarizability uncertainty

a.u.

[51]

discoverers

str

The discoverers of the element

discovery_location

str

The location where the element was discovered

discovery_year

int

The year the element was discovered

electron_affinity

float

Electron affinity([3])

eV

[6, 23]

electrons

int

Number of electrons

electrophilicity

float

Electrophilicity index

eV

[39]

en_allen

float

Allen’s scale of electronegativity([4])

eV

[31, 32]

en_ghosh

float

Ghosh’s scale of electronegativity

[18]

en_mulliken

float

Mulliken’s scale of electronegativity

eV

[36]

en_pauling

float

Pauling’s scale of electronegativity

[23]

econf

str

Ground state electron configuration

evaporation_heat

float

Evaporation heat

kJ/mol

fusion_heat

float

Fusion heat

kJ/mol

gas_basicity

float

Gas basicity

kJ/mol

[23]

geochemical_class

str

Geochemical classification

[59]

glawe_number

int

Glawe’s number (scale)

[19]

goldschmidt_class

str

Goldschmidt classification

[59, 60]

group

int

Group in periodic table

heat_of_formation

float

Heat of formation

kJ/mol

[23]

inchi

str

International Chemical Identifier

[24]

ionenergy

tuple

Ionization energies

eV

[26]

ionic_radii

list

Ionic and crystal radii in pm([8])

pm

[29, 52]

is_monoisotopic

bool

Is the element monoisotopic

is_radioactive

bool

Is the element radioactive

isotopes

list

Isotopes

jmol_color

str

Element color in Jmol convention

HEX

[64]

lattice_constant

float

Lattice constant

Angstrom

lattice_structure

str

Lattice structure code

mass_number

int

Mass number (most abundant isotope)

melting_point

float

Melting temperature

K

[22]

mendeleev_number

int

Mendeleev’s number([5])

[41, 57]

metallic_radius

float

Single-bond metallic radius

pm

[1]

metallic_radius_c12

float

Metallic radius with 12 nearest neighbors

pm

[1]

molar_heat_capacity

float

Molar heat capacity @ 25 C, 1 bar

J/(mol K)

[23]

molcas_gv_color

str

Element color in MOCAS GV convention

HEX

[65]

name

str

Name in English

name_origin

str

Origin of the name

neutrons

int

Number of neutrons (most abundant isotope)

oxistates

list

Commonly occurring oxidation states

[67]

nist_webbook_url

str

URL for the NIST Chemistry WebBook

[38]

oxistates

list

Oxidation states

period

int

Period in periodic table

pettifor_number

float

Pettifor scale

[41]

proton_affinity

float

Proton affinity

kJ/mol

[23]

protons

int

Number of protons

sconst

float

Nuclear charge screening constants([6])

[14, 15]

series

int

Index to chemical series

sources

str

Sources of the element

specific_heat_capacity

float

Specific heat capacity @ 25 C, 1 bar

J/(g K)

[23]

symbol

str

Chemical symbol

thermal_conductivity

float

Thermal conductivity @25 C

W/(m K)

triple_point_pressure

float

Triple point pressure

kPa

[22]

triple_point_temperature

float

Triple point temperature

K

[22]

uses

str

Applications of the element

vdw_radius

float

Van der Waals radius

pm

[23]

vdw_radius_alvarez

float

Van der Waals radius according to Alvarez([7])

pm

[5, 58]

vdw_radius_batsanov

float

Van der Waals radius according to Batsanov

pm

[8]

vdw_radius_bondi

float

Van der Waals radius according to Bondi

pm

[9]

vdw_radius_dreiding

float

Van der Waals radius from the DREIDING FF

pm

[34]

vdw_radius_mm3

float

Van der Waals radius from the MM3 FF

pm

[3]

vdw_radius_rt

float

Van der Waals radius according to Rowland and Taylor

pm

[48]

vdw_radius_truhlar

float

Van der Waals radius according to Truhlar

pm

[33]

vdw_radius_uff

float

Van der Waals radius from the UFF

pm

[47]

Isotopes

Name

Type

Comment

Unit

Data Source

abundance

float

Relative Abundance

[25]

abundance_uncertainty

float

Uncertainty of relative abundance

[25]

atomic_number

int

Atomic number

decay_modes

obj

Decay modes with intensities

[25]

discovery_year

int

Year the isotope was discovered

[25]

g_factor

float

Nuclear g-factor

[55]

g_factor_uncertainty

float

Uncertainty of the nuclear g-factor

[55]

half_life

float

Half life of the isotope

[25]

half_life_uncertainty

float

Uncertainty of the half life

[25]

half_life_unit

str

Unit in which the half life is given

[25]

is_radioactive

bool

Is the isotope radioactive

[62]

mass

float

Atomic mass

Da

[62]

mass_number

int

Mass number of the isotope

[62]

mass_uncertainty

float

Uncertainty of the atomic mass

Da

[62]

parity

str

Parity, if present, it can be either + or -

[25]

quadrupole_moment

float

Nuclear electric quadrupole moment

b [100 fm2]

[54]

quadrupole_moment_uncertainty

float

Nuclear electric quadrupole moment

b [100 fm2]

[54]

spin

str

Nuclear spin quantum number

[25]

Isotope Decay Modes

Name

Type

Comment

Unit

Data Source

isotope_id

int

ID of the isotope

mode

str

ASCII symbol of the decay mode

[25]

relation

str

Uncertainty of relative abundance

[25]

intensity

float

Intensity of the decay mode

%

[25]

is_allowed_not_observed

bool

If True decay mode is energetically allowed, but not experimentally observed

[25]

is_observed_intensity_unknown

bool

If True decay mode is observed, but its intensity is not experimentally known

[25]

The different modes in the table are stores as ASCII representations for compatibility. The table below provides explanations of the symbols.

ASCII

Unicode

Description

A

\(\alpha\)

\(\alpha\) emission

p

p

proton emission

2p

2p

2-proton emission

n

n

neutron emission

2n

2n

2-neutron emission

EC

\(\epsilon\)

electron capture

e+

\(e^{+}\)

positron emission

B+

\(\beta^{+}\)

\(\beta^{+}\) decay (\(\beta^{+}=\epsilon+e^{+}\))

B-

\(\beta^{-}\)

\(\beta^{-}\) decay

2B-

2\(\beta^{-}\)

double \(\beta^{-}\) decay

2B+

2\(\beta^{+}\)

double \(\beta^{+}\) decay

B-n

\(\beta^{-}\) n

\(\beta^{-}\)-delayed neutron emission

B-2n

\(\beta^{-}\) 2n

\(\beta^{-}\)-delayed 2-neutron emission

B-3n

\(\beta^{-}\) 3n

\(\beta^{-}\)-delayed 3-neutron emission

B+p

\(\beta^{+}\) p

\(\beta^{+}\)-delayed proton emission

B+2p

\(\beta^{+}\) 2p

\(\beta^{+}\)-delayed 2-proton emission

B+3p

\(\beta^{+}\) 3p

\(\beta^{+}\)-delayed 3-proton emission

B-A

\(\beta^{-}\alpha\)

\(\beta^{-}\)-delayed \(\alpha\) emission

B+A

\(\beta^{+}\alpha\)

\(\beta^{+}\)-delayed \(\alpha\) emission

B-d

\(\beta^{-}\) d

\(\beta^{-}\)-delayed deuteron emission

B-t

\(\beta^{-}\) t

\(\beta^{-}\)-delayed triton emission

IT

IT

internal transition

SF

SF

spontaneous fission

B+SF

\(\beta^{+}\) SF

\(\beta^{+}\)-delayed fission

B-SF

\(\beta^{-}\) SF

\(\beta^{-}\)-delayed fission

24Ne

24Ne

heavy cluster emission

Data Footnotes