All 4 Uses of

accord
in
Hiroshima, by John Hersey

This building, perched beside and over the water of the Kyo River, and next to the bridge of the same name, contained thirty rooms for thirty patients and their kinsfolk — for, according to Japanese custom, when a person falls sick and goes to a hospital, one or more members of his family go and live there with him, to cook for him, bathe, massage, and read to him, and to offer incessant familial sympathy, without which a Japanese patient would be miserable indeed.†
Chpt 1 *

according to = as stated by; or in agreement with

This private estate was far enough away from the explosion so that its bamboos, pines, laurel, and maples were still alive, and the green place invited refugees — partly because they believed that if the Americans came back, they would bomb only buildings; partly because the foliage seemed a center of coolness and life, and the estate's exquisitely precise rock gardens, with their quiet pools and arching bridges, were very Japanese, normal, secure; and also partly (according to some who were there) because of an irresistible, atavistic urge to hide under leaves.†
Chpt 2

But in the next three or four days, her hair kept falling out of its own accord, until she was quite bald.†
Chpt 4 *

own accord = own mind -- voluntarily (without anyone asking)

He had had an older brother, who, according to the custom of Japanese medical families, had been expected to succeed to the father's practice; the second son would have to make his own way, and in 1939, urged by the propaganda of the time to seek a fortune in the vast undeveloped reaches of China, Terufumi Sasaki had gone there and had studied at the Japanese Eastern Medical University, in Tsingtao.†
Chpt 5

according to = as stated by; or in agreement with

Definitions:

(1) (accord as in: according to, or in accord with)
in keeping with; or in agreement/harmony/unity with
This meaning of accord is often seen in the form according to or accordingly where it can take on more specific meanings. For example:
- "According to Kim, ..." -- as stated by
- "To each according to her ability." -- based upon
- "Points are scored according to how well they perform." -- depending upon
- "The dose is calculated according to body weight." -- in proportion to
- "We got a flat tire. Accordingly, I pulled to the side of the road." -- because of what was just said; or as a result
(2) (accord as in: reached an accord)
an agreement

In this sense, accord can refer to a formal agreement (such as one written between two countries) or an informal agreement (such as an unvoiced consensus about what should be done).
(3) (accord as in: done of her own accord)
mind

This sense of accord is typically seen in the form own accord or one accord.
(4) (accord as in: accord her the respect deserved)
to give someone special treatment -- especially respect