A novel method is described for producing an atomic hydrogen material at low pressure, thus far only in microscopic amounts. Hydrogen gas is absorbed in a K-promoted iron oxide catalyst (a hydrogen-abstraction catalyst) and desorbs as clusters containing H atoms at low pressure and at a temperature of < 900 K. The clusters are of the Rydberg matter (RM) type and de-excite from their initial excited state to their lowest state of excitation with a final interatomic distance of 150 pm, which is measured in the experiments. The atomic hydrogen material thus formed is concluded to be metallic by comparison with shock-wave compression experiments. A reliable value of the atomic binding energy is not known from experiments, but a theoretical tentative value for the bonding distance of 150 pin is 163 kJ mol(-1). With such a binding energy, the H(RM) or H(l) material has the highest energy content of any fuel (except nuclear fuel) at 175 MJ kg(-1) and a density of 0.5-0.7 kg dm(-3) depending upon the exact structure. The stability against transformation to hydrogen gas is not known but may be sufficient for many applications. Thus, atomic condensed hydrogen may become an important future energy carrier.