Solid phase
Official name
Low density amorphous water ice
Secondary names
amorphous ice; LDA ice
Type
Family
molecular solid
Class
hydrogen bonded molecular solid
Compound type
inorganic molecular solid
Chemical composition
Formula
$H_2O$
Chemical formula
H2O
Elemental formula
H2 O
Isotope mixture type
terrestrial abundance
2.0
  Formula Name Family Number min-max Mole fraction Isotope mole fraction State Relevance
$H_2O$ Water molecule 1 1.0 1.0 pure main
Chemical functions
  Function Number
$R-OH$ 2
Chemical bonds
  Bond Number
$-O \dots H-$ 4
$-O-H$ 2
Class
molecular solids with hydrogen bonded molecules (03)
Type
homomolecular H-bonded solids (03.01)
Group
H2O polymorphs (03.01.01)
Equivalent liquid
Liquid water
Phase name
LDA water ice
Phase type
amorphous
Crystal system
amorphous
Crystal class
N/A
Comments
no non-hydrogen-bonded water molecules, except dangling bonds
Molar mass
18.0153 $g/mol$
Density
0.94 $g/cm^3$
State NTP
liquid
Phase transitions
Phase transition type Other phases Temperature - Pressure
solid-solid H2O VIII from ice VIII only: 130K (1 bar)
solid-solid HDA ice from HDA: 120K (1 bar), to HDA: 77K (0.5 GPa)
solid-solid VHDA from VHDA only: 77-127K (0.11 GPa)
Phase transitions comments
LDA ice is metastable and can form by warming of high density amorphous ice and high pressure ices VHDA and ice VIII
Refringence type
isotropic
Refringence sign
no
Birefringence
0
Pure color
colorless
Color
colorless
Diaphaneity
transparent
Luster
vitreous
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